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37 .Nd configures ZFS file systems
44 .Oo Fl o Ar property Ns = Ns Ar value Oc Ns ...
50 .Oo Fl o Ar property Ns = Ns Ar value Oc Ns ...
51 .Fl V Ar size Ar volume
55 .Ar filesystem Ns | Ns Ar volume
59 .Ar filesystem Ns | Ns Ar volume Ns @ Ns Ar snap Ns
60 .Oo % Ns Ar snap Ns Oo , Ns Ar snap Ns Oo % Ns Ar snap Oc Oc Oc Ns ...
63 .Ar filesystem Ns | Ns Ar volume Ns # Ns Ar bookmark
67 .Oo Fl o Ar property Ns = Ns Ar value Oc Ns ...
68 .Ar filesystem Ns @ Ns Ar snapname Ns | Ns Ar volume Ns @ Ns Ar snapname Ns ...
76 .Oo Fl o Ar property Ns = Ns Ar value Oc Ns ...
77 .Ar snapshot Ar filesystem Ns | Ns Ar volume
84 .Ar filesystem Ns | Ns Ar volume Ns | Ns Ar snapshot
85 .Ar filesystem Ns | Ns Ar volume Ns | Ns Ar snapshot
89 .Ar filesystem Ns | Ns Ar volume
90 .Ar filesystem Ns | Ns Ar volume
94 .Ar snapshot Ar snapshot
97 .Op Fl r Ns | Ns Fl d Ar depth
99 .Oo Fl o Ar property Ns Oo , Ns Ar property Oc Ns ... Oc
100 .Oo Fl s Ar property Oc Ns ...
101 .Oo Fl S Ar property Oc Ns ...
102 .Oo Fl t Ar type Ns Oo , Ns Ar type Oc Ns ... Oc
103 .Oo Ar filesystem Ns | Ns Ar volume Ns | Ns Ar snapshot Oc Ns ...
106 .Ar property Ns = Ns Ar value Oo Ar property Ns = Ns Ar value Oc Ns ...
107 .Ar filesystem Ns | Ns Ar volume Ns | Ns Ar snapshot Ns ...
110 .Op Fl r Ns | Ns Fl d Ar depth
112 .Oo Fl o Ar field Ns Oo , Ns Ar field Oc Ns ... Oc
113 .Oo Fl s Ar source Ns Oo , Ns Ar source Oc Ns ... Oc
114 .Oo Fl t Ar type Ns Oo , Ns Ar type Oc Ns ... Oc
115 .Cm all | Ar property Ns Oo , Ns Ar property Oc Ns ...
116 .Ar filesystem Ns | Ns Ar volume Ns | Ns Ar snapshot Ns | Ns Ar bookmark Ns ...
120 .Ar property Ar filesystem Ns | Ns Ar volume Ns | Ns Ar snapshot Ns ...
130 .Fl a | Ar filesystem
134 .Oo Fl o Ar field Ns Oo , Ns Ar field Oc Ns ... Oc
135 .Oo Fl s Ar field Oc Ns ...
136 .Oo Fl S Ar field Oc Ns ...
137 .Oo Fl t Ar type Ns Oo , Ns Ar type Oc Ns ... Oc
138 .Ar filesystem Ns | Ns Ar snapshot
142 .Oo Fl o Ar field Ns Oo , Ns Ar field Oc Ns ... Oc
143 .Oo Fl s Ar field Oc Ns ...
144 .Oo Fl S Ar field Oc Ns ...
145 .Oo Fl t Ar type Ns Oo , Ns Ar type Oc Ns ... Oc
146 .Ar filesystem Ns | Ns Ar snapshot
153 .Fl a | Ar filesystem
157 .Fl a | Ar filesystem Ns | Ns Ar mountpoint
160 .Fl a | Ar filesystem
163 .Fl a | Ar filesystem Ns | Ns Ar mountpoint
166 .Ar snapshot bookmark
170 .Op Oo Fl I Ns | Ns Fl i Oc Ar snapshot
175 .Op Fl i Ar snapshot Ns | Ns Ar bookmark
176 .Ar filesystem Ns | Ns Ar volume Ns | Ns Ar snapshot
180 .Fl t Ar receive_resume_token
184 .Op Fl o Sy origin Ns = Ns Ar snapshot
185 .Op Fl o Ar property Ns = Ns Ar value
187 .Ar filesystem Ns | Ns Ar volume Ns | Ns Ar snapshot
191 .Op Fl d Ns | Ns Fl e
192 .Op Fl o Sy origin Ns = Ns Ar snapshot
193 .Op Fl o Ar property Ns = Ns Ar value
199 .Ar filesystem Ns | Ns Ar volume
202 .Ar filesystem Ns | Ns Ar volume
206 .Ar user Ns | Ns Ar group Ns Oo , Ns Ar user Ns | Ns Ar group Oc Ns ...
207 .Ar perm Ns | Ns @ Ns Ar setname Ns Oo , Ns Ar perm Ns | Ns @ Ns
208 .Ar setname Oc Ns ...
209 .Ar filesystem Ns | Ns Ar volume
213 .Fl e Ns | Ns Sy everyone
214 .Ar perm Ns | Ns @ Ns Ar setname Ns Oo , Ns Ar perm Ns | Ns @ Ns
215 .Ar setname Oc Ns ...
216 .Ar filesystem Ns | Ns Ar volume
220 .Ar perm Ns | Ns @ Ns Ar setname Ns Oo , Ns Ar perm Ns | Ns @ Ns
221 .Ar setname Oc Ns ...
222 .Ar filesystem Ns | Ns Ar volume
225 .Fl s No @ Ns Ar setname
226 .Ar perm Ns | Ns @ Ns Ar setname Ns Oo , Ns Ar perm Ns | Ns @ Ns
227 .Ar setname Oc Ns ...
228 .Ar filesystem Ns | Ns Ar volume
232 .Ar user Ns | Ns Ar group Ns Oo , Ns Ar user Ns | Ns Ar group Oc Ns ...
233 .Oo Ar perm Ns | Ns @ Ns Ar setname Ns Oo , Ns Ar perm Ns | Ns @ Ns
234 .Ar setname Oc Ns ... Oc
235 .Ar filesystem Ns | Ns Ar volume
239 .Fl e Ns | Ns Sy everyone
240 .Oo Ar perm Ns | Ns @ Ns Ar setname Ns Oo , Ns Ar perm Ns | Ns @ Ns
241 .Ar setname Oc Ns ... Oc
242 .Ar filesystem Ns | Ns Ar volume
247 .Oo Ar perm Ns | Ns @ Ns Ar setname Ns Oo , Ns Ar perm Ns | Ns @ Ns
248 .Ar setname Oc Ns ... Oc
249 .Ar filesystem Ns | Ns Ar volume
253 .Fl s @ Ns Ar setname
254 .Oo Ar perm Ns | Ns @ Ns Ar setname Ns Oo , Ns Ar perm Ns | Ns @ Ns
255 .Ar setname Oc Ns ... Oc
256 .Ar filesystem Ns | Ns Ar volume
260 .Ar tag Ar snapshot Ns ...
268 .Ar tag Ar snapshot Ns ...
272 .Ar snapshot Ar snapshot Ns | Ns Ar filesystem
276 .Op Fl m Ar memory_limit
282 .Op Fl L Ar keylocation
283 .Fl a | Ar filesystem
287 .Fl a | Ar filesystem
291 .Op Fl o Ar keylocation Ns = Ns Ar value
292 .Op Fl o Ar keyformat Ns = Ns Ar value
293 .Op Fl o Ar pbkdf2iters Ns = Ns Ar value
303 command configures ZFS datasets within a ZFS storage pool, as described in
305 A dataset is identified by a unique path within the ZFS namespace.
308 pool/{filesystem,volume,snapshot}
311 where the maximum length of a dataset name is
315 A dataset can be one of the following:
316 .Bl -tag -width "file system"
318 A ZFS dataset of type
320 can be mounted within the standard system namespace and behaves like other file
322 While ZFS file systems are designed to be POSIX compliant, known issues exist
323 that prevent compliance in some cases.
324 Applications that depend on standards conformance might fail due to non-standard
325 behavior when checking file system free space.
327 A logical volume exported as a raw or block device.
328 This type of dataset should only be used under special circumstances.
329 File systems are typically used in most environments.
331 A read-only version of a file system or volume at a given point in time.
333 .Ar filesystem Ns @ Ns Ar name
335 .Ar volume Ns @ Ns Ar name .
339 but without the hold on on-disk data. It can be used as the source of a send
340 (but not for a receive). It is specified as
341 .Ar filesystem Ns # Ns Ar name
343 .Ar volume Ns # Ns Ar name .
345 .Ss ZFS File System Hierarchy
346 A ZFS storage pool is a logical collection of devices that provide space for
348 A storage pool is also the root of the ZFS file system hierarchy.
350 The root of the pool can be accessed as a file system, such as mounting and
351 unmounting, taking snapshots, and setting properties.
352 The physical storage characteristics, however, are managed by the
358 for more information on creating and administering pools.
360 A snapshot is a read-only copy of a file system or volume.
361 Snapshots can be created extremely quickly, and initially consume no additional
362 space within the pool.
363 As data within the active dataset changes, the snapshot consumes more data than
364 would otherwise be shared with the active dataset.
366 Snapshots can have arbitrary names.
367 Snapshots of volumes can be cloned or rolled back, visibility is determined
370 property of the parent volume.
372 File system snapshots can be accessed under the
374 directory in the root of the file system.
375 Snapshots are automatically mounted on demand and may be unmounted at regular
377 The visibility of the
379 directory can be controlled by the
383 A bookmark is like a snapshot, a read-only copy of a file system or volume.
384 Bookmarks can be created extremely quickly, compared to snapshots, and they
385 consume no additional space within the pool. Bookmarks can also have arbitrary
386 names, much like snapshots.
388 Unlike snapshots, bookmarks can not be accessed through the filesystem in any
389 way. From a storage standpoint a bookmark just provides a way to reference
390 when a snapshot was created as a distinct object. Bookmarks are initially
391 tied to a snapshot, not the filesystem or volume, and they will survive if the
392 snapshot itself is destroyed. Since they are very light weight there's little
393 incentive to destroy them.
395 A clone is a writable volume or file system whose initial contents are the same
397 As with snapshots, creating a clone is nearly instantaneous, and initially
398 consumes no additional space.
400 Clones can only be created from a snapshot.
401 When a snapshot is cloned, it creates an implicit dependency between the parent
403 Even though the clone is created somewhere else in the dataset hierarchy, the
404 original snapshot cannot be destroyed as long as a clone exists.
407 property exposes this dependency, and the
409 command lists any such dependencies, if they exist.
411 The clone parent-child dependency relationship can be reversed by using the
416 file system to become a clone of the specified file system, which makes it
417 possible to destroy the file system that the clone was created from.
419 Creating a ZFS file system is a simple operation, so the number of file systems
420 per system is likely to be numerous.
421 To cope with this, ZFS automatically manages mounting and unmounting file
422 systems without the need to edit the
425 All automatically managed file systems are mounted by ZFS at boot time.
427 By default, file systems are mounted under
431 is the name of the file system in the ZFS namespace.
432 Directories are created and destroyed as needed.
434 A file system can also have a mount point set in the
437 This directory is created as needed, and ZFS automatically mounts the file
439 .Nm zfs Cm mount Fl a
446 property can be inherited, so if
452 automatically inherits a mount point of
453 .Pa /export/stuff/user .
459 prevents the file system from being mounted.
461 If needed, ZFS file systems can also be managed with traditional tools
467 If a file system's mount point is set to
469 ZFS makes no attempt to manage the file system, and the administrator is
470 responsible for mounting and unmounting the file system. Because pools must
471 be imported before a legacy mount can succeed, administrators should ensure
472 that legacy mounts are only attempted after the zpool import process
473 finishes at boot time. For example, on machines using systemd, the mount
476 .Nm x-systemd.requires=zfs-import.target
478 will ensure that the zfs-import completes before systemd attempts mounting
479 the filesystem. See systemd.mount(5) for details.
481 Deduplication is the process for removing redundant data at the block level,
482 reducing the total amount of data stored. If a file system has the
484 property enabled, duplicate data blocks are removed synchronously. The result
485 is that only unique data is stored and common components are shared among files.
487 Deduplicating data is a very resource-intensive operation. It is generally
488 recommended that you have at least 1.25 GiB of RAM per 1 TiB of storage when
489 you enable deduplication. Calculating the exact requirement depends heavily
490 on the type of data stored in the pool.
492 Enabling deduplication on an improperly-designed system can result in
493 performance issues (slow IO and administrative operations). It can potentially
494 lead to problems importing a pool due to memory exhaustion. Deduplication
495 can consume significant processing power (CPU) and memory as well as generate
498 Before creating a pool with deduplication enabled, ensure that you have planned
499 your hardware requirements appropriately and implemented appropriate recovery
500 practices, such as regular backups. As an alternative to deduplication
503 as a less resource-intensive alternative.
504 .Ss Native Properties
505 Properties are divided into two types, native properties and user-defined
510 Native properties either export internal statistics or control ZFS behavior.
511 In addition, native properties are either editable or read-only.
512 User properties have no effect on ZFS behavior, but you can use them to annotate
513 datasets in a way that is meaningful in your environment.
514 For more information about user properties, see the
518 Every dataset has a set of properties that export statistics about the dataset
519 as well as control various behaviors.
520 Properties are inherited from the parent unless overridden by the child.
521 Some properties apply only to certain types of datasets
522 .Pq file systems, volumes, or snapshots .
524 The values of numeric properties can be specified using human-readable suffixes
534 The following are all valid
537 .Li 1536M, 1.5g, 1.50GB .
539 The values of non-numeric properties are case sensitive and must be lowercase,
546 The following native properties consist of read-only statistics about the
548 These properties can be neither set, nor inherited.
549 Native properties apply to all dataset types unless otherwise noted.
550 .Bl -tag -width "usedbyrefreservation"
552 The amount of space available to the dataset and all its children, assuming that
553 there is no other activity in the pool.
554 Because space is shared within a pool, availability can be limited by any number
555 of factors, including physical pool size, quotas, reservations, or other
556 datasets within the pool.
558 This property can also be referred to by its shortened column name,
561 For non-snapshots, the compression ratio achieved for the
563 space of this dataset, expressed as a multiplier.
566 property includes descendant datasets, and, for clones, does not include the
567 space shared with the origin snapshot.
573 Compression can be turned on by running:
574 .Nm zfs Cm set Sy compression Ns = Ns Sy on Ar dataset .
578 The transaction group (txg) in which the dataset was created. Bookmarks have
581 as the snapshot they are initially tied to. This property is suitable for
582 ordering a list of snapshots, e.g. for incremental send and receive.
584 The time this dataset was created.
586 For snapshots, this property is a comma-separated list of filesystems or volumes
587 which are clones of this snapshot.
590 property is this snapshot.
593 property is not empty, then this snapshot can not be destroyed
600 The roles of origin and clone can be swapped by promoting the clone with the
606 if the snapshot has been marked for deferred destroy by using the
607 .Nm zfs Cm destroy Fl d
609 Otherwise, the property is
611 .It Sy encryptionroot
612 For encrypted datasets, indicates where the dataset is currently inheriting its
613 encryption key from. Loading or unloading a key for the
615 will implicitly load / unload the key for any inheriting datasets (see
618 .Nm zfs Cm unload-key
620 Clones will always share an
621 encryption key with their origin. See the
624 .It Sy filesystem_count
625 The total number of filesystems and volumes that exist under this location in
627 This value is only available when a
629 has been set somewhere in the tree under which the dataset resides.
631 Indicates if an encryption key is currently loaded into ZFS. The possible
640 .Nm zfs Cm unload-key .
642 The 64 bit GUID of this dataset or bookmark which does not change over its
643 entire lifetime. When a snapshot is sent to another pool, the received
644 snapshot has the same GUID. Thus, the
646 is suitable to identify a snapshot across pools.
647 .It Sy logicalreferenced
648 The amount of space that is
650 accessible by this dataset.
654 The logical space ignores the effect of the
658 properties, giving a quantity closer to the amount of data that applications
660 However, it does include space consumed by metadata.
662 This property can also be referred to by its shortened column name,
665 The amount of space that is
667 consumed by this dataset and all its descendents.
671 The logical space ignores the effect of the
675 properties, giving a quantity closer to the amount of data that applications
677 However, it does include space consumed by metadata.
679 This property can also be referred to by its shortened column name,
682 For file systems, indicates whether the file system is currently mounted.
683 This property can be either
688 For cloned file systems or volumes, the snapshot from which the clone was
693 .It Sy receive_resume_token
694 For filesystems or volumes which have saved partially-completed state from
696 this opaque token can be provided to
698 to resume and complete the
701 The amount of data that is accessible by this dataset, which may or may not be
702 shared with other datasets in the pool.
703 When a snapshot or clone is created, it initially references the same amount of
704 space as the file system or snapshot it was created from, since its contents are
707 This property can also be referred to by its shortened column name,
709 .It Sy refcompressratio
710 The compression ratio achieved for the
712 space of this dataset, expressed as a multiplier.
716 .It Sy snapshot_count
717 The total number of snapshots that exist under this location in the dataset
719 This value is only available when a
721 has been set somewhere in the tree under which the dataset resides.
729 The amount of space consumed by this dataset and all its descendents.
730 This is the value that is checked against this dataset's quota and reservation.
731 The space used does not include this dataset's reservation, but does take into
732 account the reservations of any descendent datasets.
733 The amount of space that a dataset consumes from its parent, as well as the
734 amount of space that is freed if this dataset is recursively destroyed, is the
735 greater of its space used and its reservation.
737 The used space of a snapshot
742 is space that is referenced exclusively by this snapshot.
743 If this snapshot is destroyed, the amount of
746 Space that is shared by multiple snapshots isn't accounted for in this metric.
747 When a snapshot is destroyed, space that was previously shared with this
748 snapshot can become unique to snapshots adjacent to it, thus changing the used
749 space of those snapshots.
750 The used space of the latest snapshot can also be affected by changes in the
754 space of a snapshot is a subset of the
756 space of the snapshot.
758 The amount of space used, available, or referenced does not take into account
760 Pending changes are generally accounted for within a few seconds.
761 Committing a change to a disk using
765 does not necessarily guarantee that the space usage information is updated
770 properties decompose the
772 properties into the various reasons that space is used.
775 .Sy usedbychildren No +
776 .Sy usedbydataset No +
777 .Sy usedbyrefreservation No +
778 .Sy usedbysnapshots .
779 These properties are only available for datasets created on
783 .It Sy usedbychildren
784 The amount of space used by children of this dataset, which would be freed if
785 all the dataset's children were destroyed.
787 The amount of space used by this dataset itself, which would be freed if the
788 dataset were destroyed
789 .Po after first removing any
791 and destroying any necessary snapshots or descendents
793 .It Sy usedbyrefreservation
794 The amount of space used by a
796 set on this dataset, which would be freed if the
799 .It Sy usedbysnapshots
800 The amount of space consumed by snapshots of this dataset.
801 In particular, it is the amount of space that would be freed if all of this
802 dataset's snapshots were destroyed.
803 Note that this is not simply the sum of the snapshots'
805 properties because space can be shared by multiple snapshots.
806 .It Sy userused Ns @ Ns Em user
807 The amount of space consumed by the specified user in this dataset.
808 Space is charged to the owner of each file, as displayed by
810 The amount of space charged is displayed by
816 subcommand for more information.
818 Unprivileged users can access only their own space usage.
819 The root user, or a user who has been granted the
823 can access everyone's usage.
826 .Sy userused Ns @ Ns Em ...
827 properties are not displayed by
828 .Nm zfs Cm get Sy all .
829 The user's name must be appended after the @ symbol, using one of the following
831 .Bl -bullet -width ""
845 .Sy joe.smith@mydomain
854 Files created on Linux always have POSIX owners.
855 .It Sy userobjused Ns @ Ns Em user
858 property is similar to
860 but instead it counts the number of objects consumed by a user. This property
861 counts all objects allocated on behalf of the user, it may differ from the
862 results of system tools such as
867 is set on a file system additional objects will be created per-file to store
868 extended attributes. These additional objects are reflected in the
870 value and are counted against the user's
872 When a file system is configured to use
874 no additional internal objects are normally required.
876 This property is set to the number of user holds on this snapshot.
877 User holds are set by using the
880 .It Sy groupused Ns @ Ns Em group
881 The amount of space consumed by the specified group in this dataset.
882 Space is charged to the group of each file, as displayed by
885 .Sy userused Ns @ Ns Em user
886 property for more information.
888 Unprivileged users can only access their own groups' space usage.
889 The root user, or a user who has been granted the
893 can access all groups' usage.
894 .It Sy groupobjused Ns @ Ns Em group
895 The number of objects consumed by the specified group in this dataset.
896 Multiple objects may be charged to the group for each file when extended
897 attributes are in use. See the
898 .Sy userobjused Ns @ Ns Em user
899 property for more information.
901 Unprivileged users can only access their own groups' space usage.
902 The root user, or a user who has been granted the
906 can access all groups' usage.
908 For volumes, specifies the block size of the volume.
911 cannot be changed once the volume has been written, so it should be set at
912 volume creation time.
915 for volumes is 8 Kbytes.
916 Any power of 2 from 512 bytes to 128 Kbytes is valid.
918 This property can also be referred to by its shortened column name,
923 by this dataset, that was written since the previous snapshot
924 .Pq i.e. that is not referenced by the previous snapshot .
925 .It Sy written Ns @ Ns Em snapshot
928 space written to this dataset since the specified snapshot.
929 This is the space that is referenced by this dataset but was not referenced by
930 the specified snapshot.
934 may be specified as a short snapshot name
935 .Po just the part after the
938 in which case it will be interpreted as a snapshot in the same filesystem as
942 may be a full snapshot name
943 .Po Em filesystem Ns @ Ns Em snapshot Pc ,
944 which for clones may be a snapshot in the origin's filesystem
945 .Pq or the origin of the origin's filesystem, etc.
948 The following native properties can be used to change the behavior of a ZFS
952 .Sy aclinherit Ns = Ns Sy discard Ns | Ns Sy noallow Ns | Ns
953 .Sy restricted Ns | Ns Sy passthrough Ns | Ns Sy passthrough-x
955 Controls how ACEs are inherited when files and directories are created.
956 .Bl -tag -width "passthrough-x"
958 does not inherit any ACEs.
960 only inherits inheritable ACEs that specify
968 permissions when the ACE is inherited.
970 inherits all inheritable ACEs without any modifications.
979 ACEs inherit the execute permission only if the file creation mode also requests
983 When the property value is set to
985 files are created with a mode determined by the inheritable ACEs.
986 If no inheritable ACEs exist that affect the mode, then the mode is set in
987 accordance to the requested mode from the application.
991 property does not apply to posix ACLs.
992 .It Sy acltype Ns = Ns Sy off Ns | Ns Sy noacl Ns | Ns Sy posixacl
993 Controls whether ACLs are enabled and if so what type of ACL to use.
994 .Bl -tag -width "posixacl"
996 default, when a file system has the
998 property set to off then ACLs are disabled.
1003 indicates posix ACLs should be used. Posix ACLs are specific to Linux and are
1004 not functional on other platforms. Posix ACLs are stored as an extended
1005 attribute and therefore will not overwrite any existing NFSv4 ACLs which
1009 To obtain the best performance when setting
1011 users are strongly encouraged to set the
1013 property. This will result in the posix ACL being stored more efficiently on
1014 disk. But as a consequence of this all new extended attributes will only be
1015 accessible from OpenZFS implementations which support the
1019 property for more details.
1020 .It Sy atime Ns = Ns Sy on Ns | Ns Sy off
1021 Controls whether the access time for files is updated when they are read.
1022 Turning this property off avoids producing write traffic when reading files and
1023 can result in significant performance gains, though it might confuse mailers
1024 and other similar utilities. The values
1028 are equivalent to the
1032 mount options. The default value is
1037 .It Sy canmount Ns = Ns Sy on Ns | Ns Sy off Ns | Ns Sy noauto
1038 If this property is set to
1040 the file system cannot be mounted, and is ignored by
1041 .Nm zfs Cm mount Fl a .
1042 Setting this property to
1044 is similar to setting the
1048 except that the dataset still has a normal
1050 property, which can be inherited.
1051 Setting this property to
1053 allows datasets to be used solely as a mechanism to inherit properties.
1054 One example of setting
1055 .Sy canmount Ns = Ns Sy off
1056 is to have two datasets with the same
1058 so that the children of both datasets appear in the same directory, but might
1059 have different inherited characteristics.
1063 a dataset can only be mounted and unmounted explicitly.
1064 The dataset is not mounted automatically when the dataset is created or
1065 imported, nor is it mounted by the
1066 .Nm zfs Cm mount Fl a
1067 command or unmounted by the
1068 .Nm zfs Cm unmount Fl a
1071 This property is not inherited.
1073 .Sy checksum Ns = Ns Sy on Ns | Ns Sy off Ns | Ns Sy fletcher2 Ns | Ns
1074 .Sy fletcher4 Ns | Ns Sy sha256 Ns | Ns Sy noparity Ns | Ns
1075 .Sy sha512 Ns | Ns Sy skein Ns | Ns Sy edonr
1077 Controls the checksum used to verify data integrity.
1078 The default value is
1080 which automatically selects an appropriate algorithm
1083 but this may change in future releases
1087 disables integrity checking on user data.
1090 not only disables integrity but also disables maintaining parity for user data.
1091 This setting is used internally by a dump device residing on a RAID-Z pool and
1092 should not be used by any other dataset.
1093 Disabling checksums is
1095 a recommended practice.
1102 checksum algorithms require enabling the appropriate features on the pool.
1104 .Xr zpool-features 5
1105 for more information on these algorithms.
1107 Changing this property affects only newly-written data.
1109 Salted checksum algorithms
1110 .Pq Cm edonr , skein
1111 are currently not supported for any filesystem on the boot pools.
1113 .Sy compression Ns = Ns Sy on Ns | Ns Sy off Ns | Ns Sy gzip Ns | Ns
1114 .Sy gzip- Ns Em N Ns | Ns Sy lz4 Ns | Ns Sy lzjb Ns | Ns Sy zle
1116 Controls the compression algorithm used for this dataset.
1118 Setting compression to
1120 indicates that the current default compression algorithm should be used.
1121 The default balances compression and decompression speed, with compression ratio
1122 and is expected to work well on a wide variety of workloads.
1123 Unlike all other settings for this property,
1125 does not select a fixed compression type.
1126 As new compression algorithms are added to ZFS and enabled on a pool, the
1127 default compression algorithm may change.
1128 The current default compression algorithm is either
1137 compression algorithm is a high-performance replacement for the
1140 It features significantly faster compression and decompression, as well as a
1141 moderately higher compression ratio than
1143 but can only be used on pools with the
1148 .Xr zpool-features 5
1149 for details on ZFS feature flags and the
1155 compression algorithm is optimized for performance while providing decent data
1160 compression algorithm uses the same compression as the
1165 level by using the value
1169 is an integer from 1
1172 .Pq best compression ratio .
1177 .Po which is also the default for
1183 compression algorithm compresses runs of zeros.
1185 This property can also be referred to by its shortened column name
1187 Changing this property affects only newly-written data.
1189 .Sy context Ns = Ns Sy none Ns | Ns
1190 .Em SELinux_User:SElinux_Role:Selinux_Type:Sensitivity_Level
1192 This flag sets the SELinux context for all files in the file system under
1193 a mount point for that file system. See
1195 for more information.
1197 .Sy fscontext Ns = Ns Sy none Ns | Ns
1198 .Em SELinux_User:SElinux_Role:Selinux_Type:Sensitivity_Level
1200 This flag sets the SELinux context for the file system file system being
1203 for more information.
1205 .Sy defcontext Ns = Ns Sy none Ns | Ns
1206 .Em SELinux_User:SElinux_Role:Selinux_Type:Sensitivity_Level
1208 This flag sets the SELinux default context for unlabeled files. See
1210 for more information.
1212 .Sy rootcontext Ns = Ns Sy none Ns | Ns
1213 .Em SELinux_User:SElinux_Role:Selinux_Type:Sensitivity_Level
1215 This flag sets the SELinux context for the root inode of the file system. See
1217 for more information.
1218 .It Sy copies Ns = Ns Sy 1 Ns | Ns Sy 2 Ns | Ns Sy 3
1219 Controls the number of copies of data stored for this dataset.
1220 These copies are in addition to any redundancy provided by the pool, for
1221 example, mirroring or RAID-Z.
1222 The copies are stored on different disks, if possible.
1223 The space used by multiple copies is charged to the associated file and dataset,
1226 property and counting against quotas and reservations.
1228 Changing this property only affects newly-written data.
1229 Therefore, set this property at file system creation time by using the
1230 .Fl o Sy copies Ns = Ns Ar N
1233 Remember that ZFS will not import a pool with a missing top-level vdev. Do
1235 create, for example a two-disk striped pool and set
1237 on some datasets thinking you have setup redundancy for them. When a disk
1238 fails you will not be able to import the pool and will have lost all of your
1240 .It Sy devices Ns = Ns Sy on Ns | Ns Sy off
1241 Controls whether device nodes can be opened on this file system.
1242 The default value is
1248 are equivalent to the
1254 .Sy dnodesize Ns = Ns Sy legacy Ns | Ns Sy auto Ns | Ns Sy 1k Ns | Ns
1255 .Sy 2k Ns | Ns Sy 4k Ns | Ns Sy 8k Ns | Ns Sy 16k
1257 Specifies a compatibility mode or literal value for the size of dnodes in the
1258 file system. The default value is
1260 Setting this property to a value other than
1262 requires the large_dnode pool feature to be enabled.
1268 if the dataset uses the
1270 property setting and the workload makes heavy use of extended attributes. This
1271 may be applicable to SELinux-enabled systems, Lustre servers, and Samba
1272 servers, for example. Literal values are supported for cases where the optimal
1273 size is known in advance and for performance testing.
1279 if you need to receive a send stream of this dataset on a pool that doesn't
1280 enable the large_dnode feature, or if you need to import this pool on a system
1281 that doesn't support the large_dnode feature.
1283 This property can also be referred to by its shortened column name,
1286 .Sy encryption Ns = Ns Sy off Ns | Ns Sy on Ns | Ns Sy aes-128-ccm Ns | Ns
1287 .Sy aes-192-ccm Ns | Ns Sy aes-256-ccm Ns | Ns Sy aes-128-gcm Ns | Ns
1288 .Sy aes-192-gcm Ns | Ns Sy aes-256-gcm
1290 Controls the encryption cipher suite (block cipher, key length, and mode) used
1291 for this dataset. Requires the
1293 feature to be enabled on the pool.
1296 to be set at dataset creation time.
1299 .Sy encryption Ns = Ns Sy on
1300 when creating a dataset indicates that the default encryption suite will be
1301 selected, which is currently
1303 In order to provide consistent data protection, encryption must be specified at
1304 dataset creation time and it cannot be changed afterwards.
1306 For more details and caveats about encryption see the
1309 .It Sy keyformat Ns = Ns Sy raw Ns | Ns Sy hex Ns | Ns Sy passphrase
1310 Controls what format the user's encryption key will be provided as. This
1311 property is only set when the dataset is encrypted.
1313 Raw keys and hex keys must be 32 bytes long (regardless of the chosen
1314 encryption suite) and must be randomly generated. A raw key can be generated
1315 with the following command:
1317 # dd if=/dev/urandom of=/path/to/output/key bs=32 count=1
1320 Passphrases must be between 8 and 512 bytes long and will be processed through
1321 PBKDF2 before being used (see the
1323 property). Even though the
1324 encryption suite cannot be changed after dataset creation, the keyformat can be
1326 .Nm zfs Cm change-key .
1328 .Sy keylocation Ns = Ns Sy prompt Ns | Ns Sy file:// Ns Em </absolute/file/path>
1330 Controls where the user's encryption key will be loaded from by default for
1334 .Nm zfs Cm mount Cm -l . This property is
1335 only set for encrypted datasets which are encryption roots. If unspecified, the
1339 Even though the encryption suite cannot be changed after dataset creation, the
1340 keylocation can be with either
1343 .Nm zfs Cm change-key .
1346 is selected ZFS will ask for the key at the command prompt when it is required
1347 to access the encrypted data (see
1349 for details). This setting will also allow the key to be passed in via STDIN,
1350 but users should be careful not to place keys which should be kept secret on
1351 the command line. If a file URI is selected, the key will be loaded from the
1352 specified absolute file path.
1353 .It Sy pbkdf2iters Ns = Ns Ar iterations
1354 Controls the number of PBKDF2 iterations that a
1356 encryption key should be run through when processing it into an encryption key.
1357 This property is only defined when encryption is enabled and a keyformat of
1359 is selected. The goal of PBKDF2 is to significantly increase the
1360 computational difficulty needed to brute force a user's passphrase. This is
1361 accomplished by forcing the attacker to run each passphrase through a
1362 computationally expensive hashing function many times before they arrive at the
1363 resulting key. A user who actually knows the passphrase will only have to pay
1364 this cost once. As CPUs become better at processing, this number should be
1365 raised to ensure that a brute force attack is still not possible. The current
1370 This property may be changed with
1371 .Nm zfs Cm change-key .
1372 .It Sy exec Ns = Ns Sy on Ns | Ns Sy off
1373 Controls whether processes can be executed from within this file system.
1374 The default value is
1380 are equivalent to the
1385 .It Sy filesystem_limit Ns = Ns Em count Ns | Ns Sy none
1386 Limits the number of filesystems and volumes that can exist under this point in
1388 The limit is not enforced if the user is allowed to change the limit.
1390 .Sy filesystem_limit
1393 a descendent of a filesystem that already has a
1394 .Sy filesystem_limit
1395 does not override the ancestor's
1396 .Sy filesystem_limit ,
1397 but rather imposes an additional limit.
1398 This feature must be enabled to be used
1400 .Xr zpool-features 5
1402 .It Sy mountpoint Ns = Ns Pa path Ns | Ns Sy none Ns | Ns Sy legacy
1403 Controls the mount point used for this file system.
1406 section for more information on how this property is used.
1410 property is changed for a file system, the file system and any children that
1411 inherit the mount point are unmounted.
1414 then they remain unmounted.
1415 Otherwise, they are automatically remounted in the new location if the property
1420 or if they were mounted before the property was changed.
1421 In addition, any shared file systems are unshared and shared in the new
1423 .It Sy nbmand Ns = Ns Sy on Ns | Ns Sy off
1424 Controls whether the file system should be mounted with
1426 .Pq Non Blocking mandatory locks .
1427 This is used for SMB clients.
1428 Changes to this property only take effect when the file system is umounted and
1432 for more information on
1434 mounts. This property is not used on Linux.
1435 .It Sy overlay Ns = Ns Sy off Ns | Ns Sy on
1436 Allow mounting on a busy directory or a directory which already contains
1437 files or directories. This is the default mount behavior for Linux file systems.
1438 For consistency with OpenZFS on other platforms overlay mounts are
1442 to enable overlay mounts.
1443 .It Sy primarycache Ns = Ns Sy all Ns | Ns Sy none Ns | Ns Sy metadata
1444 Controls what is cached in the primary cache
1446 If this property is set to
1448 then both user data and metadata is cached.
1449 If this property is set to
1451 then neither user data nor metadata is cached.
1452 If this property is set to
1454 then only metadata is cached.
1455 The default value is
1457 .It Sy quota Ns = Ns Em size Ns | Ns Sy none
1458 Limits the amount of space a dataset and its descendents can consume.
1459 This property enforces a hard limit on the amount of space used.
1460 This includes all space consumed by descendents, including file systems and
1462 Setting a quota on a descendent of a dataset that already has a quota does not
1463 override the ancestor's quota, but rather imposes an additional limit.
1465 Quotas cannot be set on volumes, as the
1467 property acts as an implicit quota.
1468 .It Sy snapshot_limit Ns = Ns Em count Ns | Ns Sy none
1469 Limits the number of snapshots that can be created on a dataset and its
1473 on a descendent of a dataset that already has a
1475 does not override the ancestor's
1476 .Sy snapshot_limit ,
1477 but rather imposes an additional limit.
1478 The limit is not enforced if the user is allowed to change the limit.
1479 For example, this means that recursive snapshots taken from the global zone are
1480 counted against each delegated dataset within a zone.
1481 This feature must be enabled to be used
1483 .Xr zpool-features 5
1485 .It Sy userquota@ Ns Em user Ns = Ns Em size Ns | Ns Sy none
1486 Limits the amount of space consumed by the specified user.
1487 User space consumption is identified by the
1488 .Sy userspace@ Ns Em user
1491 Enforcement of user quotas may be delayed by several seconds.
1492 This delay means that a user might exceed their quota before the system notices
1493 that they are over quota and begins to refuse additional writes with the
1497 .Nm zfs Cm userspace
1498 subcommand for more information.
1500 Unprivileged users can only access their own groups' space usage.
1501 The root user, or a user who has been granted the
1505 can get and set everyone's quota.
1507 This property is not available on volumes, on file systems before version 4, or
1508 on pools before version 15.
1510 .Sy userquota@ Ns Em ...
1511 properties are not displayed by
1512 .Nm zfs Cm get Sy all .
1513 The user's name must be appended after the
1515 symbol, using one of the following forms:
1523 .Em POSIX numeric ID
1530 .Sy joe.smith@mydomain
1539 Files created on Linux always have POSIX owners.
1540 .It Sy userobjquota@ Ns Em user Ns = Ns Em size Ns | Ns Sy none
1545 but it limits the number of objects a user can create. Please refer to
1547 for more information about how objects are counted.
1548 .It Sy groupquota@ Ns Em group Ns = Ns Em size Ns | Ns Sy none
1549 Limits the amount of space consumed by the specified group.
1550 Group space consumption is identified by the
1551 .Sy groupused@ Ns Em group
1554 Unprivileged users can access only their own groups' space usage.
1555 The root user, or a user who has been granted the
1559 can get and set all groups' quotas.
1560 .It Sy groupobjquota@ Ns Em group Ns = Ns Em size Ns | Ns Sy none
1565 but it limits number of objects a group can consume. Please refer to
1567 for more information about how objects are counted.
1568 .It Sy readonly Ns = Ns Sy on Ns | Ns Sy off
1569 Controls whether this dataset can be modified.
1570 The default value is
1576 are equivalent to the
1582 This property can also be referred to by its shortened column name,
1584 .It Sy recordsize Ns = Ns Em size
1585 Specifies a suggested block size for files in the file system.
1586 This property is designed solely for use with database workloads that access
1587 files in fixed-size records.
1588 ZFS automatically tunes block sizes according to internal algorithms optimized
1589 for typical access patterns.
1591 For databases that create very large files but access them in small random
1592 chunks, these algorithms may be suboptimal.
1595 greater than or equal to the record size of the database can result in
1596 significant performance gains.
1597 Use of this property for general purpose file systems is strongly discouraged,
1598 and may adversely affect performance.
1600 The size specified must be a power of two greater than or equal to 512 and less
1601 than or equal to 128 Kbytes.
1604 feature is enabled on the pool, the size may be up to 1 Mbyte.
1606 .Xr zpool-features 5
1607 for details on ZFS feature flags.
1609 Changing the file system's
1611 affects only files created afterward; existing files are unaffected.
1613 This property can also be referred to by its shortened column name,
1615 .It Sy redundant_metadata Ns = Ns Sy all Ns | Ns Sy most
1616 Controls what types of metadata are stored redundantly.
1617 ZFS stores an extra copy of metadata, so that if a single block is corrupted,
1618 the amount of user data lost is limited.
1619 This extra copy is in addition to any redundancy provided at the pool level
1620 .Pq e.g. by mirroring or RAID-Z ,
1621 and is in addition to an extra copy specified by the
1624 .Pq up to a total of 3 copies .
1625 For example if the pool is mirrored,
1626 .Sy copies Ns = Ns 2 ,
1628 .Sy redundant_metadata Ns = Ns Sy most ,
1629 then ZFS stores 6 copies of most metadata, and 4 copies of data and some
1634 ZFS stores an extra copy of all metadata.
1635 If a single on-disk block is corrupt, at worst a single block of user data
1644 ZFS stores an extra copy of most types of metadata.
1645 This can improve performance of random writes, because less metadata must be
1647 In practice, at worst about 100 blocks
1652 of user data can be lost if a single on-disk block is corrupt.
1653 The exact behavior of which metadata blocks are stored redundantly may change in
1656 The default value is
1658 .It Sy refquota Ns = Ns Em size Ns | Ns Sy none
1659 Limits the amount of space a dataset can consume.
1660 This property enforces a hard limit on the amount of space used.
1661 This hard limit does not include space used by descendents, including file
1662 systems and snapshots.
1663 .It Sy refreservation Ns = Ns Em size Ns | Ns Sy none
1664 The minimum amount of space guaranteed to a dataset, not including its
1666 When the amount of space used is below this value, the dataset is treated as if
1667 it were taking up the amount of space specified by
1668 .Sy refreservation .
1671 reservation is accounted for in the parent datasets' space used, and counts
1672 against the parent datasets' quotas and reservations.
1676 is set, a snapshot is only allowed if there is enough free pool space outside of
1677 this reservation to accommodate the current number of
1679 bytes in the dataset.
1681 This property can also be referred to by its shortened column name,
1683 .It Sy relatime Ns = Ns Sy on Ns | Ns Sy off
1684 Controls the manner in which the access time is updated when
1686 is set. Turning this property on causes the access time to be updated relative
1687 to the modify or change time. Access time is only updated if the previous
1688 access time was earlier than the current modify or change time or if the
1689 existing access time hasn't been updated within the past 24 hours. The default
1696 are equivalent to the
1701 .It Sy reservation Ns = Ns Em size Ns | Ns Sy none
1702 The minimum amount of space guaranteed to a dataset and its descendants.
1703 When the amount of space used is below this value, the dataset is treated as if
1704 it were taking up the amount of space specified by its reservation.
1705 Reservations are accounted for in the parent datasets' space used, and count
1706 against the parent datasets' quotas and reservations.
1708 This property can also be referred to by its shortened column name,
1710 .It Sy secondarycache Ns = Ns Sy all Ns | Ns Sy none Ns | Ns Sy metadata
1711 Controls what is cached in the secondary cache
1713 If this property is set to
1715 then both user data and metadata is cached.
1716 If this property is set to
1718 then neither user data nor metadata is cached.
1719 If this property is set to
1721 then only metadata is cached.
1722 The default value is
1724 .It Sy setuid Ns = Ns Sy on Ns | Ns Sy off
1725 Controls whether the setuid bit is respected for the file system.
1726 The default value is
1732 are equivalent to the
1737 .It Sy sharesmb Ns = Ns Sy on Ns | Ns Sy off Ns | Ns Em opts
1738 Controls whether the file system is shared by using
1739 .Sy Samba USERSHARES
1740 and what options are to be used. Otherwise, the file system is automatically
1741 shared and unshared with the
1745 commands. If the property is set to on, the
1747 command is invoked to create a
1750 Because SMB shares requires a resource name, a unique resource name is
1751 constructed from the dataset name. The constructed name is a copy of the
1752 dataset name except that the characters in the dataset name, which would be
1753 invalid in the resource name, are replaced with underscore (_) characters.
1754 Linux does not currently support additional options which might be available
1761 the file systems are unshared.
1763 The share is created with the ACL (Access Control List) "Everyone:F" ("F"
1764 stands for "full permissions", ie. read and write permissions) and no guest
1765 access (which means Samba must be able to authenticate a real user, system
1766 passwd/shadow, LDAP or smbpasswd based) by default. This means that any
1767 additional access control (disallow specific user specific access etc) must
1768 be done on the underlying file system.
1769 .It Sy sharenfs Ns = Ns Sy on Ns | Ns Sy off Ns | Ns Em opts
1770 Controls whether the file system is shared via NFS, and what options are to be
1772 A file system with a
1778 command and entries in the
1781 Otherwise, the file system is automatically shared and unshared with the
1786 If the property is set to
1788 the dataset is shared using the default options:
1790 .Em sec=sys,rw,crossmnt,no_subtree_check,no_root_squash
1794 for the meaning of the default options. Otherwise, the
1796 command is invoked with options equivalent to the contents of this property.
1800 property is changed for a dataset, the dataset and any children inheriting the
1801 property are re-shared with the new options, only if the property was previously
1803 or if they were shared before the property was changed.
1804 If the new property is
1806 the file systems are unshared.
1807 .It Sy logbias Ns = Ns Sy latency Ns | Ns Sy throughput
1808 Provide a hint to ZFS about handling of synchronous requests in this dataset.
1814 ZFS will use pool log devices
1816 to handle the requests at low latency.
1821 ZFS will not use configured pool log devices.
1822 ZFS will instead optimize synchronous operations for global pool throughput and
1823 efficient use of resources.
1824 .It Sy snapdev Ns = Ns Sy hidden Ns | Ns Sy visible
1825 Controls whether the volume snapshot devices under
1826 .Em /dev/zvol/<pool>
1827 are hidden or visible. The default value is
1829 .It Sy snapdir Ns = Ns Sy hidden Ns | Ns Sy visible
1830 Controls whether the
1832 directory is hidden or visible in the root of the file system as discussed in
1836 The default value is
1838 .It Sy sync Ns = Ns Sy standard Ns | Ns Sy always Ns | Ns Sy disabled
1839 Controls the behavior of synchronous requests
1840 .Pq e.g. fsync, O_DSYNC .
1844 specified behavior of ensuring all synchronous requests are written to stable
1845 storage and all devices are flushed to ensure data is not cached by device
1847 .Pq this is the default .
1849 causes every file system transaction to be written and flushed before its
1850 system call returns.
1851 This has a large performance penalty.
1853 disables synchronous requests.
1854 File system transactions are only committed to stable storage periodically.
1855 This option will give the highest performance.
1856 However, it is very dangerous as ZFS would be ignoring the synchronous
1857 transaction demands of applications such as databases or NFS.
1858 Administrators should only use this option when the risks are understood.
1859 .It Sy version Ns = Ns Em N Ns | Ns Sy current
1860 The on-disk version of this file system, which is independent of the pool
1862 This property can only be set to later supported versions.
1866 .It Sy volsize Ns = Ns Em size
1867 For volumes, specifies the logical size of the volume.
1868 By default, creating a volume establishes a reservation of equal size.
1869 For storage pools with a version number of 9 or higher, a
1874 are reflected in an equivalent change to the reservation
1880 can only be set to a multiple of
1884 The reservation is kept equal to the volume's logical size to prevent unexpected
1885 behavior for consumers.
1886 Without the reservation, the volume could run out of space, resulting in
1887 undefined behavior or data corruption, depending on how the volume is used.
1888 These effects can also occur when the volume size is changed while it is in use
1889 .Pq particularly when shrinking the size .
1890 Extreme care should be used when adjusting the volume size.
1892 Though not recommended, a
1895 .Qq thin provisioning
1897 can be created by specifying the
1900 .Nm zfs Cm create Fl V
1901 command, or by changing the reservation after the volume has been created.
1904 is a volume where the reservation is less then the volume size.
1905 Consequently, writes to a sparse volume can fail with
1907 when the pool is low on space.
1908 For a sparse volume, changes to
1910 are not reflected in the reservation.
1911 .It Sy volmode Ns = Ns Cm default | full | geom | dev | none
1912 This property specifies how volumes should be exposed to the OS.
1915 exposes volumes as fully fledged block devices, providing maximal
1916 functionality. The value
1918 is just an alias for
1920 and is kept for compatibility.
1923 hides its partitions.
1924 Volumes with property set to
1926 are not exposed outside ZFS, but can be snapshoted, cloned, replicated, etc,
1927 that can be suitable for backup purposes.
1930 means that volumes exposition is controlled by system-wide tunable
1937 are encoded as 1, 2 and 3 respectively.
1938 The default values is
1940 .It Sy vscan Ns = Ns Sy on Ns | Ns Sy off
1941 Controls whether regular files should be scanned for viruses when a file is
1943 In addition to enabling this property, the virus scan service must also be
1944 enabled for virus scanning to occur.
1945 The default value is
1947 This property is not used on Linux.
1948 .It Sy xattr Ns = Ns Sy on Ns | Ns Sy off Ns | Ns Sy sa
1949 Controls whether extended attributes are enabled for this file system. Two
1950 styles of extended attributes are supported either directory based or system
1953 The default value of
1955 enables directory based extended attributes. This style of extended attribute
1956 imposes no practical limit on either the size or number of attributes which
1957 can be set on a file. Although under Linux the
1961 system calls limit the maximum size to 64K. This is the most compatible
1962 style of extended attribute and is supported by all OpenZFS implementations.
1964 System attribute based xattrs can be enabled by setting the value to
1966 The key advantage of this type of xattr is improved performance. Storing
1967 extended attributes as system attributes significantly decreases the amount of
1968 disk IO required. Up to 64K of data may be stored per-file in the space
1969 reserved for system attributes. If there is not enough space available for
1970 an extended attribute then it will be automatically written as a directory
1971 based xattr. System attribute based extended attributes are not accessible
1972 on platforms which do not support the
1976 The use of system attribute based xattrs is strongly encouraged for users of
1977 SELinux or posix ACLs. Both of these features heavily rely of extended
1978 attributes and benefit significantly from the reduced access time.
1984 are equivalent to the
1989 .It Sy zoned Ns = Ns Sy on Ns | Ns Sy off
1990 Controls whether the dataset is managed from a non-global zone. Zones are a
1991 Solaris feature and are not relevant on Linux. The default value is
1995 The following three properties cannot be changed after the file system is
1996 created, and therefore, should be set when the file system is created.
1997 If the properties are not set with the
2001 commands, these properties are inherited from the parent dataset.
2002 If the parent dataset lacks these properties due to having been created prior to
2003 these features being supported, the new file system will have the default values
2004 for these properties.
2007 .Sy casesensitivity Ns = Ns Sy sensitive Ns | Ns
2008 .Sy insensitive Ns | Ns Sy mixed
2010 Indicates whether the file name matching algorithm used by the file system
2011 should be case-sensitive, case-insensitive, or allow a combination of both
2013 The default value for the
2021 file systems have case-sensitive file names.
2027 property indicates that the file system can support requests for both
2028 case-sensitive and case-insensitive matching behavior.
2029 Currently, case-insensitive matching behavior on a file system that supports
2030 mixed behavior is limited to the SMB server product.
2031 For more information about the
2033 value behavior, see the "ZFS Administration Guide".
2035 .Sy normalization Ns = Ns Sy none Ns | Ns Sy formC Ns | Ns
2036 .Sy formD Ns | Ns Sy formKC Ns | Ns Sy formKD
2038 Indicates whether the file system should perform a
2040 normalization of file names whenever two file names are compared, and which
2041 normalization algorithm should be used.
2042 File names are always stored unmodified, names are normalized as part of any
2044 If this property is set to a legal value other than
2048 property was left unspecified, the
2050 property is automatically set to
2052 The default value of the
2056 This property cannot be changed after the file system is created.
2057 .It Sy utf8only Ns = Ns Sy on Ns | Ns Sy off
2058 Indicates whether the file system should reject file names that include
2059 characters that are not present in the
2062 If this property is explicitly set to
2064 the normalization property must either not be explicitly set or be set to
2066 The default value for the
2070 This property cannot be changed after the file system is created.
2074 .Sy casesensitivity ,
2078 properties are also new permissions that can be assigned to non-privileged users
2079 by using the ZFS delegated administration feature.
2080 .Ss "Temporary Mount Point Properties"
2081 When a file system is mounted, either through
2083 for legacy mounts or the
2085 command for normal file systems, its mount options are set according to its
2087 The correlation between properties and mount options is as follows:
2089 PROPERTY MOUNT OPTION
2091 canmount auto/noauto
2095 relatime relatime/norelatime
2100 In addition, these options can be set on a per-mount basis using the
2102 option, without affecting the property that is stored on disk.
2103 The values specified on the command line override the values stored in the
2107 option is an alias for
2108 .Sy nodevices Ns \&, Ns Sy nosetuid .
2109 These properties are reported as
2114 If the properties are changed while the dataset is mounted, the new setting
2115 overrides any temporary settings.
2116 .Ss "User Properties"
2117 In addition to the standard native properties, ZFS supports arbitrary user
2119 User properties have no effect on ZFS behavior, but applications or
2120 administrators can use them to annotate datasets
2121 .Pq file systems, volumes, and snapshots .
2123 User property names must contain a colon
2125 character to distinguish them from native properties.
2126 They may contain lowercase letters, numbers, and the following punctuation
2135 The expected convention is that the property name is divided into two portions
2137 .Em module Ns \&: Ns Em property ,
2138 but this namespace is not enforced by ZFS.
2139 User property names can be at most 256 characters, and cannot begin with a dash
2142 When making programmatic use of user properties, it is strongly suggested to use
2147 component of property names to reduce the chance that two
2148 independently-developed packages use the same property name for different
2151 The values of user properties are arbitrary strings, are always inherited, and
2152 are never validated.
2153 All of the commands that operate on properties
2154 .Po Nm zfs Cm list ,
2159 can be used to manipulate both native properties and user properties.
2162 command to clear a user property.
2163 If the property is not defined in any parent dataset, it is removed entirely.
2164 Property values are limited to 8192 bytes.
2165 .Ss ZFS Volumes as Swap
2166 ZFS volumes may be used as swap devices. After creating the volume with the
2167 .Nm zfs Cm create Fl V
2168 command set up and enable the swap area using the
2172 commands. Do not swap to a file on a ZFS file system. A ZFS swap file
2173 configuration is not supported.
2177 feature allows for the creation of encrypted filesystems and volumes.
2179 will encrypt all user data including file and zvol data, file attributes,
2180 ACLs, permission bits, directory listings, FUID mappings, and userused /
2183 will not encrypt metadata related to the pool structure, including dataset
2184 names, dataset hierarchy, file size, file holes, and dedup tables. Key rotation
2185 is managed internally by the kernel module and changing the user's key does not
2186 require re-encrypting the entire dataset. Datasets can be scrubbed, resilvered,
2187 renamed, and deleted without the encryption keys being loaded (see the
2189 subcommand for more info on key loading).
2191 Creating an encrypted dataset requires specifying the
2195 properties at creation time, along with an optional
2199 After entering an encryption key, the
2200 created dataset will become an encryption root. Any descendant datasets will
2201 inherit their encryption key from the encryption root by default, meaning that
2202 loading, unloading, or changing the key for the encryption root will implicitly
2203 do the same for all inheriting datasets. If this inheritance is not desired,
2206 when creating the child dataset or use
2207 .Nm zfs Cm change-key
2208 to break an existing relationship, creating a new encryption root on the child.
2209 Note that the child's
2211 may match that of the parent while still creating a new encryption root, and
2214 property alone does not create a new encryption root; this would simply use a
2215 different cipher suite with the same key as its encryption root. The one
2216 exception is that clones will always use their origin's encryption key.
2217 As a result of this exception, some encryption-related properties (namely
2223 do not inherit like other ZFS properties and instead use the value determined
2224 by their encryption root. Encryption root inheritance can be tracked via the
2229 Encryption changes the behavior of a few
2231 operations. Encryption is applied after compression so compression ratios are
2232 preserved. Normally checksums in ZFS are 256 bits long, but for encrypted data
2233 the checksum is 128 bits of the user-chosen checksum and 128 bits of MAC from
2234 the encryption suite, which provides additional protection against maliciously
2235 altered data. Deduplication is still possible with encryption enabled but for
2236 security, datasets will only dedup against themselves, their snapshots, and
2239 There are a few limitations on encrypted datasets. Encrypted data cannot be
2242 feature. Encrypted datasets may not have
2243 .Sy copies Ns = Ns Em 3
2244 since the implementation stores some encryption metadata where the third copy
2245 would normally be. Since compression is applied before encryption datasets may
2246 be vulnerable to a CRIME-like attack if applications accessing the data allow
2247 for it. Deduplication with encryption will leak information about which blocks
2248 are equivalent in a dataset and will incur an extra CPU cost per block written.
2250 All subcommands that modify state are logged persistently to the pool in their
2254 Displays a help message.
2259 .Oo Fl o Ar property Ns = Ns Ar value Oc Ns ...
2262 Creates a new ZFS file system.
2263 The file system is automatically mounted according to the
2265 property inherited from the parent.
2266 .Bl -tag -width "-o"
2267 .It Fl o Ar property Ns = Ns Ar value
2268 Sets the specified property as if the command
2269 .Nm zfs Cm set Ar property Ns = Ns Ar value
2270 was invoked at the same time the dataset was created.
2271 Any editable ZFS property can also be set at creation time.
2274 options can be specified.
2275 An error results if the same property is specified in multiple
2279 Creates all the non-existing parent datasets.
2280 Datasets created in this manner are automatically mounted according to the
2282 property inherited from their parent.
2283 Any property specified on the command line using the
2286 If the target filesystem already exists, the operation completes successfully.
2292 .Op Fl b Ar blocksize
2293 .Oo Fl o Ar property Ns = Ns Ar value Oc Ns ...
2294 .Fl V Ar size Ar volume
2296 Creates a volume of the given size.
2297 The volume is exported as a block device in
2298 .Pa /dev/zvol/path ,
2301 is the name of the volume in the ZFS namespace.
2302 The size represents the logical size as exported by the device.
2303 By default, a reservation of equal size is created.
2306 is automatically rounded up to the nearest 128 Kbytes to ensure that the volume
2307 has an integral number of blocks regardless of
2309 .Bl -tag -width "-b"
2310 .It Fl b Ar blocksize
2312 .Fl o Sy volblocksize Ns = Ns Ar blocksize .
2313 If this option is specified in conjunction with
2314 .Fl o Sy volblocksize ,
2315 the resulting behavior is undefined.
2316 .It Fl o Ar property Ns = Ns Ar value
2317 Sets the specified property as if the
2318 .Nm zfs Cm set Ar property Ns = Ns Ar value
2319 command was invoked at the same time the dataset was created.
2320 Any editable ZFS property can also be set at creation time.
2323 options can be specified.
2324 An error results if the same property is specified in multiple
2328 Creates all the non-existing parent datasets.
2329 Datasets created in this manner are automatically mounted according to the
2331 property inherited from their parent.
2332 Any property specified on the command line using the
2335 If the target filesystem already exists, the operation completes successfully.
2337 Creates a sparse volume with no reservation.
2341 .Sx Native Properties
2342 section for more information about sparse volumes.
2348 .Ar filesystem Ns | Ns Ar volume
2350 Destroys the given dataset.
2351 By default, the command unshares any file systems that are currently shared,
2352 unmounts any file systems that are currently mounted, and refuses to destroy a
2353 dataset that has active dependents
2354 .Pq children or clones .
2355 .Bl -tag -width "-R"
2357 Recursively destroy all dependents, including cloned file systems outside the
2360 Force an unmount of any file systems using the
2363 This option has no effect on non-file systems or unmounted file systems.
2368 No data will be deleted.
2369 This is useful in conjunction with the
2373 flags to determine what data would be deleted.
2375 Print machine-parsable verbose information about the deleted data.
2377 Recursively destroy all children.
2379 Print verbose information about the deleted data.
2382 Extreme care should be taken when applying either the
2386 options, as they can destroy large portions of a pool and cause unexpected
2387 behavior for mounted file systems in use.
2392 .Ar filesystem Ns | Ns Ar volume Ns @ Ns Ar snap Ns
2393 .Oo % Ns Ar snap Ns Oo , Ns Ar snap Ns Oo % Ns Ar snap Oc Oc Oc Ns ...
2395 The given snapshots are destroyed immediately if and only if the
2399 option would have destroyed it.
2400 Such immediate destruction would occur, for example, if the snapshot had no
2401 clones and the user-initiated reference count were zero.
2403 If a snapshot does not qualify for immediate destruction, it is marked for
2405 In this state, it exists as a usable, visible snapshot until both of the
2406 preconditions listed above are met, at which point it is destroyed.
2408 An inclusive range of snapshots may be specified by separating the first and
2409 last snapshots with a percent sign.
2410 The first and/or last snapshots may be left blank, in which case the
2411 filesystem's oldest or newest snapshot will be implied.
2414 .Pq or ranges of snapshots
2415 of the same filesystem or volume may be specified in a comma-separated list of
2417 Only the snapshot's short name
2418 .Po the part after the
2421 should be specified when using a range or comma-separated list to identify
2423 .Bl -tag -width "-R"
2425 Recursively destroy all clones of these snapshots, including the clones,
2426 snapshots, and children.
2427 If this flag is specified, the
2429 flag will have no effect.
2431 Defer snapshot deletion.
2436 No data will be deleted.
2437 This is useful in conjunction with the
2441 flags to determine what data would be deleted.
2443 Print machine-parsable verbose information about the deleted data.
2446 .Pq or mark for deferred deletion
2447 all snapshots with this name in descendent file systems.
2449 Print verbose information about the deleted data.
2451 Extreme care should be taken when applying either the
2455 options, as they can destroy large portions of a pool and cause unexpected
2456 behavior for mounted file systems in use.
2461 .Ar filesystem Ns | Ns Ar volume Ns # Ns Ar bookmark
2463 The given bookmark is destroyed.
2468 .Oo Fl o Ar property Ns = Ns Ar value Oc Ns ...
2469 .Ar filesystem Ns @ Ns Ar snapname Ns | Ns Ar volume Ns @ Ns Ar snapname Ns ...
2471 Creates snapshots with the given names.
2472 All previous modifications by successful system calls to the file system are
2473 part of the snapshots.
2474 Snapshots are taken atomically, so that all snapshots correspond to the same
2477 can be used as an alias for
2478 .Nm zfs Cm snapshot.
2481 section for details.
2482 .Bl -tag -width "-o"
2483 .It Fl o Ar property Ns = Ns Ar value
2484 Sets the specified property; see
2488 Recursively create snapshots of all descendent datasets
2496 Roll back the given dataset to a previous snapshot.
2497 When a dataset is rolled back, all data that has changed since the snapshot is
2498 discarded, and the dataset reverts to the state at the time of the snapshot.
2499 By default, the command refuses to roll back to a snapshot other than the most
2501 In order to do so, all intermediate snapshots and bookmarks must be destroyed by
2508 options do not recursively destroy the child snapshots of a recursive snapshot.
2509 Only direct snapshots of the specified filesystem are destroyed by either of
2511 To completely roll back a recursive snapshot, you must rollback the individual
2513 .Bl -tag -width "-R"
2515 Destroy any more recent snapshots and bookmarks, as well as any clones of those
2520 option to force an unmount of any clone file systems that are to be destroyed.
2522 Destroy any snapshots and bookmarks more recent than the one specified.
2528 .Oo Fl o Ar property Ns = Ns Ar value Oc Ns ...
2529 .Ar snapshot Ar filesystem Ns | Ns Ar volume
2531 Creates a clone of the given snapshot.
2534 section for details.
2535 The target dataset can be located anywhere in the ZFS hierarchy, and is created
2536 as the same type as the original.
2537 .Bl -tag -width "-o"
2538 .It Fl o Ar property Ns = Ns Ar value
2539 Sets the specified property; see
2543 Creates all the non-existing parent datasets.
2544 Datasets created in this manner are automatically mounted according to the
2546 property inherited from their parent.
2547 If the target filesystem or volume already exists, the operation completes
2553 .Ar clone-filesystem
2555 Promotes a clone file system to no longer be dependent on its
2558 This makes it possible to destroy the file system that the clone was created
2560 The clone parent-child dependency relationship is reversed, so that the origin
2561 file system becomes a clone of the specified file system.
2563 The snapshot that was cloned, and any snapshots previous to this snapshot, are
2564 now owned by the promoted clone.
2565 The space they use moves from the origin file system to the promoted clone, so
2566 enough space must be available to accommodate these snapshots.
2567 No new space is consumed by this operation, but the space accounting is
2569 The promoted clone must not have any conflicting snapshot names of its own.
2572 subcommand can be used to rename any conflicting snapshots.
2577 .Ar filesystem Ns | Ns Ar volume Ns | Ns Ar snapshot
2578 .Ar filesystem Ns | Ns Ar volume Ns | Ns Ar snapshot
2584 .Ar filesystem Ns | Ns Ar volume
2585 .Ar filesystem Ns | Ns Ar volume
2587 Renames the given dataset.
2588 The new target can be located anywhere in the ZFS hierarchy, with the exception
2590 Snapshots can only be renamed within the parent file system or volume.
2591 When renaming a snapshot, the parent file system of the snapshot does not need
2592 to be specified as part of the second argument.
2593 Renamed file systems can inherit new mount points, in which case they are
2594 unmounted and remounted at the new mount point.
2595 .Bl -tag -width "-a"
2597 Force unmount any filesystems that need to be unmounted in the process.
2599 Creates all the nonexistent parent datasets.
2600 Datasets created in this manner are automatically mounted according to the
2602 property inherited from their parent.
2608 .Ar snapshot Ar snapshot
2610 Recursively rename the snapshots of all descendent datasets.
2611 Snapshots are the only dataset that can be renamed recursively.
2615 .Op Fl r Ns | Ns Fl d Ar depth
2617 .Oo Fl o Ar property Ns Oo , Ns Ar property Oc Ns ... Oc
2618 .Oo Fl s Ar property Oc Ns ...
2619 .Oo Fl S Ar property Oc Ns ...
2620 .Oo Fl t Ar type Ns Oo , Ns Ar type Oc Ns ... Oc
2621 .Oo Ar filesystem Ns | Ns Ar volume Ns | Ns Ar snapshot Oc Ns ...
2623 Lists the property information for the given datasets in tabular form.
2624 If specified, you can list property information by the absolute pathname or the
2626 By default, all file systems and volumes are displayed.
2627 Snapshots are displayed if the
2634 The following fields are displayed,
2635 .Sy name Ns \&, Ns Sy used Ns \&, Ns Sy available Ns \&, Ns Sy referenced Ns \&, Ns
2637 .Bl -tag -width "-H"
2639 Used for scripting mode.
2640 Do not print headers and separate fields by a single tab instead of arbitrary
2642 .It Fl S Ar property
2645 option, but sorts by property in descending order.
2647 Recursively display any children of the dataset, limiting the recursion to
2653 will display only the dataset and its direct children.
2654 .It Fl o Ar property
2655 A comma-separated list of properties to display.
2656 The property must be:
2659 One of the properties described in the
2660 .Sx Native Properties
2667 to display the dataset name
2671 to display space usage properties on file systems and volumes.
2672 This is a shortcut for specifying
2673 .Fl o Sy name Ns \&, Ns Sy avail Ns \&, Ns Sy used Ns \&, Ns Sy usedsnap Ns \&, Ns
2674 .Sy usedds Ns \&, Ns Sy usedrefreserv Ns \&, Ns Sy usedchild Fl t
2675 .Sy filesystem Ns \&, Ns Sy volume
2679 Display numbers in parsable
2683 Recursively display any children of the dataset on the command line.
2684 .It Fl s Ar property
2685 A property for sorting the output by column in ascending order based on the
2686 value of the property.
2687 The property must be one of the properties described in the
2689 section, or the special value
2691 to sort by the dataset name.
2692 Multiple properties can be specified at one time using multiple
2697 options are evaluated from left to right in decreasing order of importance.
2698 The following is a list of sorting criteria:
2701 Numeric types sort in numeric order.
2703 String types sort in alphabetical order.
2705 Types inappropriate for a row sort that row to the literal bottom, regardless of
2706 the specified ordering.
2709 If no sorting options are specified the existing behavior of
2713 A comma-separated list of types to display, where
2722 For example, specifying
2724 displays only snapshots.
2729 .Ar property Ns = Ns Ar value Oo Ar property Ns = Ns Ar value Oc Ns ...
2730 .Ar filesystem Ns | Ns Ar volume Ns | Ns Ar snapshot Ns ...
2732 Sets the property or list of properties to the given value(s) for each dataset.
2733 Only some properties can be edited.
2736 section for more information on what properties can be set and acceptable
2738 Numeric values can be specified as exact values, or in a human-readable form
2740 .Sy B , K , M , G , T , P , E , Z
2741 .Po for bytes, kilobytes, megabytes, gigabytes, terabytes, petabytes, exabytes,
2742 or zettabytes, respectively
2744 User properties can be set on snapshots.
2745 For more information, see the
2751 .Op Fl r Ns | Ns Fl d Ar depth
2753 .Oo Fl o Ar field Ns Oo , Ns Ar field Oc Ns ... Oc
2754 .Oo Fl s Ar source Ns Oo , Ns Ar source Oc Ns ... Oc
2755 .Oo Fl t Ar type Ns Oo , Ns Ar type Oc Ns ... Oc
2756 .Cm all | Ar property Ns Oo , Ns Ar property Oc Ns ...
2757 .Ar filesystem Ns | Ns Ar volume Ns | Ns Ar snapshot Ns | Ns Ar bookmark Ns ...
2759 Displays properties for the given datasets.
2760 If no datasets are specified, then the command displays properties for all
2761 datasets on the system.
2762 For each property, the following columns are displayed:
2765 property Property name
2766 value Property value
2767 source Property source. Can either be local, default,
2768 temporary, inherited, or none (-).
2771 All columns are displayed by default, though this can be controlled by using the
2774 This command takes a comma-separated list of properties as described in the
2775 .Sx Native Properties
2782 can be used to display all properties that apply to the given dataset's type
2783 .Pq filesystem, volume, snapshot, or bookmark .
2784 .Bl -tag -width "-H"
2786 Display output in a form more easily parsed by scripts.
2787 Any headers are omitted, and fields are explicitly separated by a single tab
2788 instead of an arbitrary amount of space.
2790 Recursively display any children of the dataset, limiting the recursion to
2794 will display only the dataset and its direct children.
2796 A comma-separated list of columns to display.
2797 .Sy name Ns \&, Ns Sy property Ns \&, Ns Sy value Ns \&, Ns Sy source
2798 is the default value.
2800 Display numbers in parsable
2804 Recursively display properties for any children.
2806 A comma-separated list of sources to display.
2807 Those properties coming from a source other than those in this list are ignored.
2808 Each source must be one of the following:
2815 The default value is all sources.
2817 A comma-separated list of types to display, where
2831 .Ar property Ar filesystem Ns | Ns Ar volume Ns | Ns Ar snapshot Ns ...
2833 Clears the specified property, causing it to be inherited from an ancestor,
2834 restored to default if no ancestor has the property set, or with the
2836 option reverted to the received value if one exists.
2839 section for a listing of default values, and details on which properties can be
2841 .Bl -tag -width "-r"
2843 Recursively inherit the given property for all children.
2845 Revert the property to the received value if one exists; otherwise operate as
2848 option was not specified.
2854 Displays a list of file systems that are not the most recent version.
2860 Displays a list of currently supported file system versions.
2866 .Fl a | Ar filesystem
2868 Upgrades file systems to a new on-disk version.
2869 Once this is done, the file systems will no longer be accessible on systems
2870 running older versions of the software.
2872 streams generated from new snapshots of these file systems cannot be accessed on
2873 systems running older versions of the software.
2875 In general, the file system version is independent of the pool version.
2878 for information on the
2879 .Nm zpool Cm upgrade
2882 In some cases, the file system version and the pool version are interrelated and
2883 the pool version must be upgraded before the file system version can be
2885 .Bl -tag -width "-V"
2887 Upgrade to the specified
2891 flag is not specified, this command upgrades to the most recent version.
2893 option can only be used to increase the version number, and only up to the most
2894 recent version supported by this software.
2896 Upgrade all file systems on all imported pools.
2898 Upgrade the specified file system.
2900 Upgrade the specified file system and all descendent file systems.
2906 .Oo Fl o Ar field Ns Oo , Ns Ar field Oc Ns ... Oc
2907 .Oo Fl s Ar field Oc Ns ...
2908 .Oo Fl S Ar field Oc Ns ...
2909 .Oo Fl t Ar type Ns Oo , Ns Ar type Oc Ns ... Oc
2910 .Ar filesystem Ns | Ns Ar snapshot
2912 Displays space consumed by, and quotas on, each user in the specified filesystem
2914 This corresponds to the
2915 .Sy userused@ Ns Em user ,
2916 .Sy userobjused@ Ns Em user ,
2917 .Sy userquota@ Ns Em user,
2919 .Sy userobjquota@ Ns Em user
2921 .Bl -tag -width "-H"
2923 Do not print headers, use tab-delimited output.
2925 Sort by this field in reverse order.
2929 Translate SID to POSIX ID.
2930 The POSIX ID may be ephemeral if no mapping exists.
2931 Normal POSIX interfaces
2936 perform this translation, so the
2938 option allows the output from
2939 .Nm zfs Cm userspace
2940 to be compared directly with those utilities.
2943 may lead to confusion if some files were created by an SMB user before a
2944 SMB-to-POSIX name mapping was established.
2945 In such a case, some files will be owned by the SMB entity and some by the POSIX
2949 option will report that the POSIX entity has the total usage and quota for both.
2951 Print numeric ID instead of user/group name.
2952 .It Fl o Ar field Ns Oo , Ns Ar field Oc Ns ...
2953 Display only the specified fields from the following set:
2958 The default is to display all fields.
2964 Sort output by this field.
2969 flags may be specified multiple times to sort first by one field, then by
2972 .Fl s Sy type Fl s Sy name .
2973 .It Fl t Ar type Ns Oo , Ns Ar type Oc Ns ...
2974 Print only the specified types from the following set:
2981 .Fl t Sy posixuser Ns \&, Ns Sy smbuser .
2982 The default can be changed to include group types.
2988 .Oo Fl o Ar field Ns Oo , Ns Ar field Oc Ns ... Oc
2989 .Oo Fl s Ar field Oc Ns ...
2990 .Oo Fl S Ar field Oc Ns ...
2991 .Oo Fl t Ar type Ns Oo , Ns Ar type Oc Ns ... Oc
2992 .Ar filesystem Ns | Ns Ar snapshot
2994 Displays space consumed by, and quotas on, each group in the specified
2995 filesystem or snapshot.
2996 This subcommand is identical to
2997 .Nm zfs Cm userspace ,
2998 except that the default types to display are
2999 .Fl t Sy posixgroup Ns \&, Ns Sy smbgroup .
3004 Displays all ZFS file systems currently mounted.
3010 .Fl a | Ar filesystem
3012 Mounts ZFS file systems.
3013 .Bl -tag -width "-O"
3015 Perform an overlay mount.
3018 for more information.
3020 Mount all available ZFS file systems.
3021 Invoked automatically as part of the boot process.
3023 Mount the specified filesystem.
3025 An optional, comma-separated list of mount options to use temporarily for the
3026 duration of the mount.
3028 .Sx Temporary Mount Point Properties
3029 section for details.
3031 Load keys for encrypted filesystems as they are being mounted. This is
3032 equivalent to executing
3034 on each encryption root before mounting it. Note that if a filesystem has a
3038 this will cause the terminal to interactively block after asking for the key.
3040 Report mount progress.
3046 .Fl a | Ar filesystem Ns | Ns Ar mountpoint
3048 Unmounts currently mounted ZFS file systems.
3049 .Bl -tag -width "-a"
3051 Unmount all available ZFS file systems.
3052 Invoked automatically as part of the shutdown process.
3053 .It Ar filesystem Ns | Ns Ar mountpoint
3054 Unmount the specified filesystem.
3055 The command can also be given a path to a ZFS file system mount point on the
3058 Forcefully unmount the file system, even if it is currently in use.
3063 .Fl a | Ar filesystem
3065 Shares available ZFS file systems.
3066 .Bl -tag -width "-a"
3068 Share all available ZFS file systems.
3069 Invoked automatically as part of the boot process.
3071 Share the specified filesystem according to the
3076 File systems are shared when the
3085 .Fl a | Ar filesystem Ns | Ns Ar mountpoint
3087 Unshares currently shared ZFS file systems.
3088 .Bl -tag -width "-a"
3090 Unshare all available ZFS file systems.
3091 Invoked automatically as part of the shutdown process.
3092 .It Ar filesystem Ns | Ns Ar mountpoint
3093 Unshare the specified filesystem.
3094 The command can also be given a path to a ZFS file system shared on the system.
3099 .Ar snapshot bookmark
3101 Creates a bookmark of the given snapshot.
3102 Bookmarks mark the point in time when the snapshot was created, and can be used
3103 as the incremental source for a
3107 This feature must be enabled to be used.
3109 .Xr zpool-features 5
3110 for details on ZFS feature flags and the
3117 .Op Oo Fl I Ns | Ns Fl i Oc Ar snapshot
3120 Creates a stream representation of the second
3122 which is written to standard output.
3123 The output can be redirected to a file or to a different system
3124 .Po for example, using
3127 By default, a full stream is generated.
3128 .Bl -tag -width "-D"
3130 Generate a deduplicated stream.
3131 Blocks which would have been sent multiple times in the send stream will only be
3133 The receiving system must also support this feature to receive a deduplicated
3135 This flag can be used regardless of the dataset's
3137 property, but performance will be much better if the filesystem uses a
3138 dedup-capable checksum
3142 .It Fl I Ar snapshot
3143 Generate a stream package that sends all intermediary snapshots from the first
3144 snapshot to the second snapshot.
3148 .Fl i Em @a Em fs@b Ns \&; Fl i Em @b Em fs@c Ns \&; Fl i Em @c Em fs@d .
3149 The incremental source may be specified as with the
3152 .It Fl L, -large-block
3153 Generate a stream which may contain blocks larger than 128KB.
3154 This flag has no effect if the
3156 pool feature is disabled, or if the
3158 property of this filesystem has never been set above 128KB.
3159 The receiving system must have the
3161 pool feature enabled as well.
3163 .Xr zpool-features 5
3164 for details on ZFS feature flags and the
3168 Print machine-parsable verbose information about the stream package generated.
3169 .It Fl R, -replicate
3170 Generate a replication stream package, which will replicate the specified
3171 file system, and all descendent file systems, up to the named snapshot.
3172 When received, all properties, snapshots, descendent file systems, and clones
3179 flags are used in conjunction with the
3181 flag, an incremental replication stream is generated.
3182 The current values of properties, and current snapshot and file system names are
3183 set when the stream is received.
3186 flag is specified when this stream is received, snapshots and file systems that
3187 do not exist on the sending side are destroyed.
3189 Generate a more compact stream by using
3191 records for blocks which are stored more compactly on disk by the
3194 This flag has no effect if the
3196 feature is disabled.
3197 The receiving system must have the
3202 feature is active on the sending system, then the receiving system must have
3203 that feature enabled as well. Datasets that are sent with this flag may not be
3204 received as an encrypted dataset, since encrypted datasets cannot use the
3208 .Xr zpool-features 5
3209 for details on ZFS feature flags and the
3212 .It Fl c, -compressed
3213 Generate a more compact stream by using compressed WRITE records for blocks
3214 which are compressed on disk and in memory
3217 property for details
3221 feature is active on the sending system, then the receiving system must have
3222 that feature enabled as well.
3225 feature is enabled on the sending system but the
3227 option is not supplied in conjunction with
3229 then the data will be decompressed before sending so it can be split into
3230 smaller block sizes.
3232 For encrypted datasets, send data exactly as it exists on disk. This allows
3233 backups to be taken even if encryption keys are not currently loaded. The
3234 backup may then be received on an untrusted machine since that machine will
3235 not have the encryption keys to read the protected data or alter it without
3236 being detected. Upon being received, the dataset will have the same encryption
3237 keys as it did on the send side, although the
3239 property will be defaulted to
3241 if not otherwise provided. For unencrypted datasets, this flag will be
3244 Note that if you do not use this flag for sending encrypted datasets, data will
3245 be sent unencrypted and may be re-encrypted with a different encryption key on
3246 the receiving system, which will disable the ability to do a raw send to that
3247 system for incrementals.
3248 .It Fl i Ar snapshot
3249 Generate an incremental stream from the first
3251 .Pq the incremental source
3254 .Pq the incremental target .
3255 The incremental source can be specified as the last component of the snapshot
3259 character and following
3261 and it is assumed to be from the same file system as the incremental target.
3263 If the destination is a clone, the source may be the origin snapshot, which must
3266 .Em pool/fs@origin ,
3274 Do not generate any actual send data.
3275 This is useful in conjunction with the
3279 flags to determine what data will be sent.
3280 In this case, the verbose output will be written to standard output
3281 .Po contrast with a non-dry-run, where the stream is written to standard output
3282 and the verbose output goes to standard error
3285 Include the dataset's properties in the stream.
3286 This flag is implicit when
3289 The receiving system must also support this feature. Sends of encrypted datasets
3292 when using this flag.
3294 Print verbose information about the stream package generated.
3295 This information includes a per-second report of how much data has been sent.
3297 The format of the stream is committed.
3298 You will be able to receive your streams on future versions of ZFS.
3304 .Op Fl i Ar snapshot Ns | Ns Ar bookmark
3305 .Ar filesystem Ns | Ns Ar volume Ns | Ns Ar snapshot
3307 Generate a send stream, which may be of a filesystem, and may be incremental
3309 If the destination is a filesystem or volume, the pool must be read-only, or the
3310 filesystem must not be mounted.
3311 When the stream generated from a filesystem or volume is received, the default
3312 snapshot name will be
3314 .Bl -tag -width "-L"
3315 .It Fl L, -large-block
3316 Generate a stream which may contain blocks larger than 128KB.
3317 This flag has no effect if the
3319 pool feature is disabled, or if the
3321 property of this filesystem has never been set above 128KB.
3322 The receiving system must have the
3324 pool feature enabled as well.
3326 .Xr zpool-features 5
3327 for details on ZFS feature flags and the
3331 Print machine-parsable verbose information about the stream package generated.
3332 .It Fl c, -compressed
3333 Generate a more compact stream by using compressed WRITE records for blocks
3334 which are compressed on disk and in memory
3337 property for details
3341 feature is active on the sending system, then the receiving system must have
3342 that feature enabled as well.
3345 feature is enabled on the sending system but the
3347 option is not supplied in conjunction with
3349 then the data will be decompressed before sending so it can be split into
3350 smaller block sizes.
3352 For encrypted datasets, send data exactly as it exists on disk. This allows
3353 backups to be taken even if encryption keys are not currently loaded. The
3354 backup may then be received on an untrusted machine since that machine will
3355 not have the encryption keys to read the protected data or alter it without
3356 being detected. Upon being received, the dataset will have the same encryption
3357 keys as it did on the send side, although the
3359 property will be defaulted to
3361 if not otherwise provided. For unencrypted datasets, this flag will be
3364 Note that if you do not use this flag for sending encrypted datasets, data will
3365 be sent unencrypted and may be re-encrypted with a different encryption key on
3366 the receiving system, which will disable the ability to do a raw send to that
3367 system for incrementals.
3369 Generate a more compact stream by using
3371 records for blocks which are stored more compactly on disk by the
3374 This flag has no effect if the
3376 feature is disabled.
3377 The receiving system must have the
3382 feature is active on the sending system, then the receiving system must have
3383 that feature enabled as well. Datasets that are sent with this flag may not be
3384 received as an encrypted dataset, since encrypted datasets cannot use the
3388 .Xr zpool-features 5
3389 for details on ZFS feature flags and the
3392 .It Fl i Ar snapshot Ns | Ns Ar bookmark
3393 Generate an incremental send stream.
3394 The incremental source must be an earlier snapshot in the destination's history.
3395 It will commonly be an earlier snapshot in the destination's file system, in
3396 which case it can be specified as the last component of the name
3401 character and following
3404 If the incremental target is a clone, the incremental source can be the origin
3405 snapshot, or an earlier snapshot in the origin's filesystem, or the origin's
3411 Do not generate any actual send data.
3412 This is useful in conjunction with the
3416 flags to determine what data will be sent.
3417 In this case, the verbose output will be written to standard output
3418 .Po contrast with a non-dry-run, where the stream is written to standard output
3419 and the verbose output goes to standard error
3422 Print verbose information about the stream package generated.
3423 This information includes a per-second report of how much data has been sent.
3430 .Ar receive_resume_token
3432 Creates a send stream which resumes an interrupted receive.
3434 .Ar receive_resume_token
3435 is the value of this property on the filesystem or volume that was being
3437 See the documentation for
3444 .Op Fl o Sy origin Ns = Ns Ar snapshot
3445 .Op Fl o Ar property Ns = Ns Ar value
3446 .Op Fl x Ar property
3447 .Ar filesystem Ns | Ns Ar volume Ns | Ns Ar snapshot
3453 .Op Fl d Ns | Ns Fl e
3454 .Op Fl o Sy origin Ns = Ns Ar snapshot
3455 .Op Fl o Ar property Ns = Ns Ar value
3456 .Op Fl x Ar property
3459 Creates a snapshot whose contents are as specified in the stream provided on
3461 If a full stream is received, then a new file system is created as well.
3462 Streams are created using the
3464 subcommand, which by default creates a full stream.
3466 can be used as an alias for
3469 If an incremental stream is received, then the destination file system must
3470 already exist, and its most recent snapshot must match the incremental stream's
3474 the destination device link is destroyed and recreated, which means the
3476 cannot be accessed during the
3480 When a snapshot replication package stream that is generated by using the
3481 .Nm zfs Cm send Fl R
3482 command is received, any snapshots that do not exist on the sending location are
3483 destroyed by using the
3484 .Nm zfs Cm destroy Fl d
3488 .Fl o Em property Ns = Ns Ar value
3491 is specified, it applies to the effective value of the property throughout
3492 the entire subtree of replicated datasets. Effective property values will be
3497 ) on the topmost in the replicated subtree. In descendant datasets, if the
3498 property is set by the send stream, it will be overridden by forcing the
3499 property to be inherited from the top‐most file system. Received properties
3500 are retained in spite of being overridden and may be restored with
3501 .Nm zfs Cm inherit Fl S .
3503 .Fl o Sy origin Ns = Ns Em snapshot
3504 is a special case because, even if
3506 is a read-only property and cannot be set, it's allowed to receive the send
3507 stream as a clone of the given snapshot.
3509 Raw encrypted send streams (created with
3510 .Nm zfs Cm send Fl w
3511 ) may only be received as is, and cannot be re-encrypted, decrypted, or
3512 recompressed by the receive process. Unencrypted streams can be received as
3513 encrypted datasets, either through inheritance or by specifying encryption
3518 The name of the snapshot
3519 .Pq and file system, if a full stream is received
3520 that this subcommand creates depends on the argument type and the use of the
3526 If the argument is a snapshot name, the specified
3529 If the argument is a file system or volume name, a snapshot with the same name
3530 as the sent snapshot is created within the specified
3538 options are specified, the provided target snapshot name is used exactly as
3545 options cause the file system name of the target snapshot to be determined by
3546 appending a portion of the sent snapshot's name to the specified target
3550 option is specified, all but the first element of the sent snapshot's file
3552 .Pq usually the pool name
3553 is used and any required intermediate file systems within the specified one are
3557 option is specified, then only the last element of the sent snapshot's file
3559 .Pq i.e. the name of the source file system itself
3560 is used as the target file system name.
3561 .Bl -tag -width "-F"
3563 Force a rollback of the file system to the most recent snapshot before
3564 performing the receive operation.
3565 If receiving an incremental replication stream
3566 .Po for example, one generated by
3567 .Nm zfs Cm send Fl R Op Fl i Ns | Ns Fl I
3569 destroy snapshots and file systems that do not exist on the sending side.
3571 Discard the first element of the sent snapshot's file system name, using the
3572 remaining elements to determine the name of the target file system for the new
3573 snapshot as described in the paragraph above.
3575 Discard all but the last element of the sent snapshot's file system name, using
3576 that element to determine the name of the target file system for the new
3577 snapshot as described in the paragraph above.
3579 Do not actually receive the stream.
3580 This can be useful in conjunction with the
3582 option to verify the name the receive operation would use.
3583 .It Fl o Sy origin Ns = Ns Ar snapshot
3584 Forces the stream to be received as a clone of the given snapshot.
3585 If the stream is a full send stream, this will create the filesystem
3586 described by the stream as a clone of the specified snapshot.
3587 Which snapshot was specified will not affect the success or failure of the
3588 receive, as long as the snapshot does exist.
3589 If the stream is an incremental send stream, all the normal verification will be
3591 .It Fl o Em property Ns = Ns Ar value
3592 Sets the specified property as if the command
3593 .Nm zfs Cm set Em property Ns = Ns Ar value
3594 was invoked immediately before the receive. When receiving a stream from
3595 .Nm zfs Cm send Fl R ,
3596 causes the property to be inherited by all descendant datasets, as through
3597 .Nm zfs Cm inherit Em property
3598 was run on any descendant datasets that have this property set on the
3601 Any editable property can be set at receive time. Set-once properties bound
3602 to the received data, such as
3605 .Sy casesensitivity ,
3606 cannot be set at receive time even when the datasets are newly created by
3607 .Nm zfs Cm receive .
3608 Additionally both settable properties
3612 cannot be set at receive time.
3616 option may be specified multiple times, for different properties. An error
3617 results if the same property is specified in multiple
3623 If the receive is interrupted, save the partially received state, rather
3625 Interruption may be due to premature termination of the stream
3626 .Po e.g. due to network failure or failure of the remote system
3627 if the stream is being read over a network connection
3629 a checksum error in the stream, termination of the
3631 process, or unclean shutdown of the system.
3633 The receive can be resumed with a stream generated by
3634 .Nm zfs Cm send Fl t Ar token ,
3638 .Sy receive_resume_token
3639 property of the filesystem or volume which is received into.
3641 To use this flag, the storage pool must have the
3642 .Sy extensible_dataset
3645 .Xr zpool-features 5
3646 for details on ZFS feature flags.
3648 File system that is associated with the received stream is not mounted.
3650 Print verbose information about the stream and the time required to perform the
3652 .It Fl x Em property
3653 Ensures that the effective value of the specified property after the
3654 receive is unaffected by the value of that property in the send stream (if any),
3655 as if the property had been excluded from the send stream.
3657 If the specified property is not present in the send stream, this option does
3660 If a received property needs to be overridden, the effective value will be
3661 set or inherited, depending on whether the property is inheritable or not.
3663 In the case of an incremental update,
3665 leaves any existing local setting or explicit inheritance unchanged.
3669 restrictions on set-once and special properties apply equally to
3676 .Ar filesystem Ns | Ns Ar volume
3678 Abort an interrupted
3679 .Nm zfs Cm receive Fl s ,
3680 deleting its saved partially received state.
3684 .Ar filesystem Ns | Ns Ar volume
3686 Displays permissions that have been delegated on the specified filesystem or
3688 See the other forms of
3690 for more information.
3692 Delegations are supported under Linux with the exception of
3700 These permissions cannot be delegated because the Linux
3702 command restricts modifications of the global namespace to the root user.
3707 .Ar user Ns | Ns Ar group Ns Oo , Ns Ar user Ns | Ns Ar group Oc Ns ...
3708 .Ar perm Ns | Ns @ Ns Ar setname Ns Oo , Ns Ar perm Ns | Ns @ Ns
3709 .Ar setname Oc Ns ...
3710 .Ar filesystem Ns | Ns Ar volume
3715 .Fl e Ns | Ns Sy everyone
3716 .Ar perm Ns | Ns @ Ns Ar setname Ns Oo , Ns Ar perm Ns | Ns @ Ns
3717 .Ar setname Oc Ns ...
3718 .Ar filesystem Ns | Ns Ar volume
3720 Delegates ZFS administration permission for the file systems to non-privileged
3722 .Bl -tag -width "-d"
3724 Allow only for the descendent file systems.
3725 .It Fl e Ns | Ns Sy everyone
3726 Specifies that the permissions be delegated to everyone.
3727 .It Fl g Ar group Ns Oo , Ns Ar group Oc Ns ...
3728 Explicitly specify that permissions are delegated to the group.
3732 only for the specified file system.
3733 .It Fl u Ar user Ns Oo , Ns Ar user Oc Ns ...
3734 Explicitly specify that permissions are delegated to the user.
3735 .It Ar user Ns | Ns Ar group Ns Oo , Ns Ar user Ns | Ns Ar group Oc Ns ...
3736 Specifies to whom the permissions are delegated.
3737 Multiple entities can be specified as a comma-separated list.
3740 options are specified, then the argument is interpreted preferentially as the
3743 then as a user name, and lastly as a group name.
3744 To specify a user or group named
3751 To specify a group with the same name as a user, use the
3755 .Ar perm Ns | Ns @ Ns Ar setname Ns Oo , Ns Ar perm Ns | Ns @ Ns
3756 .Ar setname Oc Ns ...
3758 The permissions to delegate.
3759 Multiple permissions may be specified as a comma-separated list.
3760 Permission names are the same as ZFS subcommand and property names.
3761 See the property list below.
3762 Property set names, which begin with
3767 form below for details.
3772 options are specified, or both are, then the permissions are allowed for the
3773 file system or volume, and all of its descendents.
3775 Permissions are generally the ability to use a ZFS subcommand or change a ZFS
3777 The following permissions are available:
3780 allow subcommand Must also have the permission that is
3782 clone subcommand Must also have the 'create' ability and
3783 'mount' ability in the origin file system
3784 create subcommand Must also have the 'mount' ability
3785 destroy subcommand Must also have the 'mount' ability
3786 diff subcommand Allows lookup of paths within a dataset
3787 given an object number, and the ability
3788 to create snapshots necessary to
3790 load-key subcommand Allows loading and unloading of encryption key
3791 (see 'zfs load-key' and 'zfs unload-key').
3792 change-key subcommand Allows changing an encryption key via
3794 mount subcommand Allows mount/umount of ZFS datasets
3795 promote subcommand Must also have the 'mount' and 'promote'
3796 ability in the origin file system
3797 receive subcommand Must also have the 'mount' and 'create'
3799 rename subcommand Must also have the 'mount' and 'create'
3800 ability in the new parent
3801 rollback subcommand Must also have the 'mount' ability
3803 share subcommand Allows sharing file systems over NFS
3805 snapshot subcommand Must also have the 'mount' ability
3807 groupquota other Allows accessing any groupquota@...
3809 groupused other Allows reading any groupused@... property
3810 userprop other Allows changing any user property
3811 userquota other Allows accessing any userquota@...
3813 userused other Allows reading any userused@... property
3819 casesensitivity property
3821 compression property
3825 filesystem_limit property
3828 normalization property
3829 primarycache property
3834 refreservation property
3835 reservation property
3836 secondarycache property
3841 snapshot_limit property
3844 volblocksize property
3854 .Ar perm Ns | Ns @ Ns Ar setname Ns Oo , Ns Ar perm Ns | Ns @ Ns
3855 .Ar setname Oc Ns ...
3856 .Ar filesystem Ns | Ns Ar volume
3861 These permissions are granted
3863 to the creator of any newly-created descendent file system.
3867 .Fl s No @ Ns Ar setname
3868 .Ar perm Ns | Ns @ Ns Ar setname Ns Oo , Ns Ar perm Ns | Ns @ Ns
3869 .Ar setname Oc Ns ...
3870 .Ar filesystem Ns | Ns Ar volume
3872 Defines or adds permissions to a permission set.
3873 The set can be used by other
3875 commands for the specified file system and its descendents.
3876 Sets are evaluated dynamically, so changes to a set are immediately reflected.
3877 Permission sets follow the same naming restrictions as ZFS file systems, but the
3878 name must begin with
3880 and can be no more than 64 characters long.
3885 .Ar user Ns | Ns Ar group Ns Oo , Ns Ar user Ns | Ns Ar group Oc Ns ...
3886 .Oo Ar perm Ns | Ns @ Ns Ar setname Ns Oo , Ns Ar perm Ns | Ns @ Ns
3887 .Ar setname Oc Ns ... Oc
3888 .Ar filesystem Ns | Ns Ar volume
3893 .Fl e Ns | Ns Sy everyone
3894 .Oo Ar perm Ns | Ns @ Ns Ar setname Ns Oo , Ns Ar perm Ns | Ns @ Ns
3895 .Ar setname Oc Ns ... Oc
3896 .Ar filesystem Ns | Ns Ar volume
3902 .Oo Ar perm Ns | Ns @ Ns Ar setname Ns Oo , Ns Ar perm Ns | Ns @ Ns
3903 .Ar setname Oc Ns ... Oc
3904 .Ar filesystem Ns | Ns Ar volume
3906 Removes permissions that were granted with the
3909 No permissions are explicitly denied, so other permissions granted are still in
3911 For example, if the permission is granted by an ancestor.
3912 If no permissions are specified, then all permissions for the specified
3924 only removes the permissions that were granted to everyone, not all permissions
3925 for every user and group.
3928 command for a description of the
3931 .Bl -tag -width "-r"
3933 Recursively remove the permissions from this file system and all descendents.
3939 .Fl s No @ Ns Ar setname
3940 .Oo Ar perm Ns | Ns @ Ns Ar setname Ns Oo , Ns Ar perm Ns | Ns @ Ns
3941 .Ar setname Oc Ns ... Oc
3942 .Ar filesystem Ns | Ns Ar volume
3944 Removes permissions from a permission set.
3945 If no permissions are specified, then all permissions are removed, thus removing
3951 .Ar tag Ar snapshot Ns ...
3953 Adds a single reference, named with the
3955 argument, to the specified snapshot or snapshots.
3956 Each snapshot has its own tag namespace, and tags must be unique within that
3959 If a hold exists on a snapshot, attempts to destroy that snapshot by using the
3963 .Bl -tag -width "-r"
3965 Specifies that a hold with the given tag is applied recursively to the snapshots
3966 of all descendent file systems.
3974 Lists all existing user references for the given snapshot or snapshots.
3975 .Bl -tag -width "-r"
3977 Lists the holds that are set on the named descendent snapshots, in addition to
3978 listing the holds on the named snapshot.
3984 .Ar tag Ar snapshot Ns ...
3986 Removes a single reference, named with the
3988 argument, from the specified snapshot or snapshots.
3989 The tag must already exist for each snapshot.
3990 If a hold exists on a snapshot, attempts to destroy that snapshot by using the
3994 .Bl -tag -width "-r"
3996 Recursively releases a hold with the given tag on the snapshots of all
3997 descendent file systems.
4003 .Ar snapshot Ar snapshot Ns | Ns Ar filesystem
4005 Display the difference between a snapshot of a given filesystem and another
4006 snapshot of that filesystem from a later time or the current contents of the
4008 The first column is a character indicating the type of change, the other columns
4009 indicate pathname, new pathname
4010 .Pq in case of rename ,
4011 change in link count, and optionally file type and/or change time.
4012 The types of change are:
4014 - The path has been removed
4015 + The path has been created
4016 M The path has been modified
4017 R The path has been renamed
4019 .Bl -tag -width "-F"
4021 Display an indication of the type of file, in a manner similar to the
4037 Give more parsable tab-separated output, without header lines and without
4040 Display the path's inode change time as the first column of output.
4046 .Op Fl m Ar memory_limit
4052 as a ZFS channel program on
4055 program interface allows ZFS administrative operations to be run
4056 programmatically via a Lua script.
4057 The entire script is executed atomically, with no other administrative
4058 operations taking effect concurrently.
4059 A library of ZFS calls is made available to channel program scripts.
4060 Channel programs may only be run with root privileges.
4062 For full documentation of the ZFS channel program interface, see the manual
4067 Execution time limit, in milliseconds.
4068 If a channel program executes for longer than the provided timeout, it will
4069 be stopped and an error will be returned.
4070 The default timeout is 1000 ms, and can be set to a maximum of 10000 ms.
4071 .It Fl m Ar memory-limit
4072 Memory limit, in bytes.
4073 If a channel program attempts to allocate more memory than the given limit,
4074 it will be stopped and an error returned.
4075 The default memory limit is 10 MB, and can be set to a maximum of 100 MB.
4077 All remaining argument strings are passed directly to the channel program as
4081 for more information.
4087 .Op Fl L Ar keylocation
4088 .Fl a | Ar filesystem
4092 allowing it and all children that inherit the
4094 property to be accessed. The key will be expected in the format specified by the
4096 and location specified by the
4098 property. Note that if the
4102 the terminal will interactively wait for the key to be entered. Loading a key
4103 will not automatically mount the dataset. If that functionality is desired,
4104 .Nm zfs Cm mount Sy -l
4105 will ask for the key and mount the dataset. Once the key is loaded the
4107 property will become
4109 .Bl -tag -width "-r"
4111 Recursively loads the keys for the specified filesystem and all descendent
4114 Loads the keys for all encryption roots in all imported pools.
4118 load-key. This will cause zfs to simply check that the
4119 provided key is correct. This command may be run even if the key is already
4121 .It Fl L Ar keylocation
4126 property. This will not change the value of the property on the dataset. Note
4127 that if used with either
4132 may only be given as
4139 .Fl a | Ar filesystem
4141 Unloads a key from ZFS, removing the ability to access the dataset and all of
4142 its children that inherit the
4144 property. This requires that the dataset is not currently open or mounted. Once
4145 the key is unloaded the
4147 property will become
4149 .Bl -tag -width "-r"
4151 Recursively unloads the keys for the specified filesystem and all descendent
4154 Unloads the keys for all encryption roots in all imported pools.
4160 .Op Fl o Ar keylocation Ns = Ns Ar value
4161 .Op Fl o Ar keyformat Ns = Ns Ar value
4162 .Op Fl o Ar pbkdf2iters Ns = Ns Ar value
4172 Allows a user to change the encryption key used to access a dataset. This
4173 command requires that the existing key for the dataset is already loaded into
4174 ZFS. This command may also be used to change the
4179 properties as needed. If the dataset was not previously an encryption root it
4180 will become one. Alternatively, the
4182 flag may be provided to cause an encryption root to inherit the parent's key
4184 .Bl -tag -width "-r"
4186 Ensures the key is loaded before attempting to change the key. This is
4187 effectively equivalent to
4188 .Qq Nm zfs Cm load-key Ar filesystem ; Nm zfs Cm change-key Ar filesystem
4189 .It Fl o Ar property Ns = Ns Ar value
4190 Allows the user to set encryption key properties (
4195 ) while changing the key. This is the only way to alter
4199 after the dataset has been created.
4201 Indicates that zfs should make
4203 inherit the key of its parent. Note that this command can only be run on an
4204 encryption root that has an encrypted parent.
4210 utility exits 0 on success, 1 if an error occurs, and 2 if invalid command line
4211 options were specified.
4214 .It Sy Example 1 No Creating a ZFS File System Hierarchy
4215 The following commands create a file system named
4217 and a file system named
4221 is set for the parent file system, and is automatically inherited by the child
4224 # zfs create pool/home
4225 # zfs set mountpoint=/export/home pool/home
4226 # zfs create pool/home/bob
4228 .It Sy Example 2 No Creating a ZFS Snapshot
4229 The following command creates a snapshot named
4231 This snapshot is mounted on demand in the
4233 directory at the root of the
4237 # zfs snapshot pool/home/bob@yesterday
4239 .It Sy Example 3 No Creating and Destroying Multiple Snapshots
4240 The following command creates snapshots named
4244 and all of its descendent file systems.
4245 Each snapshot is mounted on demand in the
4247 directory at the root of its file system.
4248 The second command destroys the newly created snapshots.
4250 # zfs snapshot -r pool/home@yesterday
4251 # zfs destroy -r pool/home@yesterday
4253 .It Sy Example 4 No Disabling and Enabling File System Compression
4254 The following command disables the
4256 property for all file systems under
4258 The next command explicitly enables
4261 .Em pool/home/anne .
4263 # zfs set compression=off pool/home
4264 # zfs set compression=on pool/home/anne
4266 .It Sy Example 5 No Listing ZFS Datasets
4267 The following command lists all active file systems and volumes in the system.
4268 Snapshots are displayed if the
4276 for more information on pool properties.
4279 NAME USED AVAIL REFER MOUNTPOINT
4280 pool 450K 457G 18K /pool
4281 pool/home 315K 457G 21K /export/home
4282 pool/home/anne 18K 457G 18K /export/home/anne
4283 pool/home/bob 276K 457G 276K /export/home/bob
4285 .It Sy Example 6 No Setting a Quota on a ZFS File System
4286 The following command sets a quota of 50 Gbytes for
4289 # zfs set quota=50G pool/home/bob
4291 .It Sy Example 7 No Listing ZFS Properties
4292 The following command lists all properties for
4295 # zfs get all pool/home/bob
4296 NAME PROPERTY VALUE SOURCE
4297 pool/home/bob type filesystem -
4298 pool/home/bob creation Tue Jul 21 15:53 2009 -
4299 pool/home/bob used 21K -
4300 pool/home/bob available 20.0G -
4301 pool/home/bob referenced 21K -
4302 pool/home/bob compressratio 1.00x -
4303 pool/home/bob mounted yes -
4304 pool/home/bob quota 20G local
4305 pool/home/bob reservation none default
4306 pool/home/bob recordsize 128K default
4307 pool/home/bob mountpoint /pool/home/bob default
4308 pool/home/bob sharenfs off default
4309 pool/home/bob checksum on default
4310 pool/home/bob compression on local
4311 pool/home/bob atime on default
4312 pool/home/bob devices on default
4313 pool/home/bob exec on default
4314 pool/home/bob setuid on default
4315 pool/home/bob readonly off default
4316 pool/home/bob zoned off default
4317 pool/home/bob snapdir hidden default
4318 pool/home/bob acltype off default
4319 pool/home/bob aclinherit restricted default
4320 pool/home/bob canmount on default
4321 pool/home/bob xattr on default
4322 pool/home/bob copies 1 default
4323 pool/home/bob version 4 -
4324 pool/home/bob utf8only off -
4325 pool/home/bob normalization none -
4326 pool/home/bob casesensitivity sensitive -
4327 pool/home/bob vscan off default
4328 pool/home/bob nbmand off default
4329 pool/home/bob sharesmb off default
4330 pool/home/bob refquota none default
4331 pool/home/bob refreservation none default
4332 pool/home/bob primarycache all default
4333 pool/home/bob secondarycache all default
4334 pool/home/bob usedbysnapshots 0 -
4335 pool/home/bob usedbydataset 21K -
4336 pool/home/bob usedbychildren 0 -
4337 pool/home/bob usedbyrefreservation 0 -
4340 The following command gets a single property value.
4342 # zfs get -H -o value compression pool/home/bob
4345 The following command lists all properties with local settings for
4348 # zfs get -r -s local -o name,property,value all pool/home/bob
4350 pool/home/bob quota 20G
4351 pool/home/bob compression on
4353 .It Sy Example 8 No Rolling Back a ZFS File System
4354 The following command reverts the contents of
4356 to the snapshot named
4358 deleting all intermediate snapshots.
4360 # zfs rollback -r pool/home/anne@yesterday
4362 .It Sy Example 9 No Creating a ZFS Clone
4363 The following command creates a writable file system whose initial contents are
4365 .Em pool/home/bob@yesterday .
4367 # zfs clone pool/home/bob@yesterday pool/clone
4369 .It Sy Example 10 No Promoting a ZFS Clone
4370 The following commands illustrate how to test out changes to a file system, and
4371 then replace the original file system with the changed one, using clones, clone
4372 promotion, and renaming:
4374 # zfs create pool/project/production
4375 populate /pool/project/production with data
4376 # zfs snapshot pool/project/production@today
4377 # zfs clone pool/project/production@today pool/project/beta
4378 make changes to /pool/project/beta and test them
4379 # zfs promote pool/project/beta
4380 # zfs rename pool/project/production pool/project/legacy
4381 # zfs rename pool/project/beta pool/project/production
4382 once the legacy version is no longer needed, it can be destroyed
4383 # zfs destroy pool/project/legacy
4385 .It Sy Example 11 No Inheriting ZFS Properties
4386 The following command causes
4392 property from their parent.
4394 # zfs inherit checksum pool/home/bob pool/home/anne
4396 .It Sy Example 12 No Remotely Replicating ZFS Data
4397 The following commands send a full stream and then an incremental stream to a
4398 remote machine, restoring them into
4399 .Em poolB/received/fs@a
4401 .Em poolB/received/fs@b ,
4404 must contain the file system
4405 .Em poolB/received ,
4406 and must not initially contain
4407 .Em poolB/received/fs .
4409 # zfs send pool/fs@a | \e
4410 ssh host zfs receive poolB/received/fs@a
4411 # zfs send -i a pool/fs@b | \e
4412 ssh host zfs receive poolB/received/fs
4414 .It Sy Example 13 No Using the zfs receive -d Option
4415 The following command sends a full stream of
4416 .Em poolA/fsA/fsB@snap
4417 to a remote machine, receiving it into
4418 .Em poolB/received/fsA/fsB@snap .
4421 portion of the received snapshot's name is determined from the name of the sent
4424 must contain the file system
4425 .Em poolB/received .
4427 .Em poolB/received/fsA
4428 does not exist, it is created as an empty file system.
4430 # zfs send poolA/fsA/fsB@snap | \e
4431 ssh host zfs receive -d poolB/received
4433 .It Sy Example 14 No Setting User Properties
4434 The following example sets the user-defined
4435 .Sy com.example:department
4436 property for a dataset.
4438 # zfs set com.example:department=12345 tank/accounting
4440 .It Sy Example 15 No Performing a Rolling Snapshot
4441 The following example shows how to maintain a history of snapshots with a
4442 consistent naming scheme.
4443 To keep a week's worth of snapshots, the user destroys the oldest snapshot,
4444 renames the remaining snapshots, and then creates a new snapshot, as follows:
4446 # zfs destroy -r pool/users@7daysago
4447 # zfs rename -r pool/users@6daysago @7daysago
4448 # zfs rename -r pool/users@5daysago @6daysago
4449 # zfs rename -r pool/users@yesterday @5daysago
4450 # zfs rename -r pool/users@yesterday @4daysago
4451 # zfs rename -r pool/users@yesterday @3daysago
4452 # zfs rename -r pool/users@yesterday @2daysago
4453 # zfs rename -r pool/users@today @yesterday
4454 # zfs snapshot -r pool/users@today
4456 .It Sy Example 16 No Setting sharenfs Property Options on a ZFS File System
4457 The following commands show how to set
4459 property options to enable
4463 addresses and to enable root access for system
4469 # zfs set sharenfs='rw=@123.123.0.0/16,root=neo' tank/home
4474 for host name resolution, specify the fully qualified hostname.
4475 .It Sy Example 17 No Delegating ZFS Administration Permissions on a ZFS Dataset
4476 The following example shows how to set permissions so that user
4478 can create, destroy, mount, and take snapshots on
4484 # zfs allow cindys create,destroy,mount,snapshot tank/cindys
4485 # zfs allow tank/cindys
4486 ---- Permissions on tank/cindys --------------------------------------
4487 Local+Descendent permissions:
4488 user cindys create,destroy,mount,snapshot
4493 mount point permission is set to 755 by default, user
4495 will be unable to mount file systems under
4497 Add an ACE similar to the following syntax to provide mount point access:
4499 # chmod A+user:cindys:add_subdirectory:allow /tank/cindys
4501 .It Sy Example 18 No Delegating Create Time Permissions on a ZFS Dataset
4502 The following example shows how to grant anyone in the group
4504 to create file systems in
4506 This syntax also allows staff members to destroy their own file systems, but not
4507 destroy anyone else's file system.
4512 # zfs allow staff create,mount tank/users
4513 # zfs allow -c destroy tank/users
4514 # zfs allow tank/users
4515 ---- Permissions on tank/users ---------------------------------------
4518 Local+Descendent permissions:
4519 group staff create,mount
4521 .It Sy Example 19 No Defining and Granting a Permission Set on a ZFS Dataset
4522 The following example shows how to define and grant a permission set on the
4529 # zfs allow -s @pset create,destroy,snapshot,mount tank/users
4530 # zfs allow staff @pset tank/users
4531 # zfs allow tank/users
4532 ---- Permissions on tank/users ---------------------------------------
4534 @pset create,destroy,mount,snapshot
4535 Local+Descendent permissions:
4538 .It Sy Example 20 No Delegating Property Permissions on a ZFS Dataset
4539 The following example shows to grant the ability to set quotas and reservations
4547 # zfs allow cindys quota,reservation users/home
4548 # zfs allow users/home
4549 ---- Permissions on users/home ---------------------------------------
4550 Local+Descendent permissions:
4551 user cindys quota,reservation
4552 cindys% zfs set quota=10G users/home/marks
4553 cindys% zfs get quota users/home/marks
4554 NAME PROPERTY VALUE SOURCE
4555 users/home/marks quota 10G local
4557 .It Sy Example 21 No Removing ZFS Delegated Permissions on a ZFS Dataset
4558 The following example shows how to remove the snapshot permission from the
4567 # zfs unallow staff snapshot tank/users
4568 # zfs allow tank/users
4569 ---- Permissions on tank/users ---------------------------------------
4571 @pset create,destroy,mount,snapshot
4572 Local+Descendent permissions:
4575 .It Sy Example 22 No Showing the differences between a snapshot and a ZFS Dataset
4576 The following example shows how to see what has changed between a prior
4577 snapshot of a ZFS dataset and its current state.
4580 option is used to indicate type information for the files affected.
4582 # zfs diff -F tank/test@before tank/test
4584 M F /tank/test/linked (+1)
4585 R F /tank/test/oldname -> /tank/test/newname
4586 - F /tank/test/deleted
4587 + F /tank/test/created
4588 M F /tank/test/modified
4590 .It Sy Example 23 No Creating a bookmark
4591 The following example create a bookmark to a snapshot. This bookmark
4592 can then be used instead of snapshot in send streams.
4594 # zfs bookmark rpool@snapshot rpool#bookmark
4596 .It Sy Example 24 No Setting sharesmb Property Options on a ZFS File System
4597 The following example show how to share SMB filesystem through ZFS. Note that
4598 that a user and his/her password must be given.
4600 # smbmount //127.0.0.1/share_tmp /mnt/tmp \\
4601 -o user=workgroup/turbo,password=obrut,uid=1000
4605 .Em /etc/samba/smb.conf
4606 configuration required:
4608 Samba will need to listen to 'localhost' (127.0.0.1) for the ZFS utilities to
4609 communicate with Samba. This is the default behavior for most Linux
4612 Samba must be able to authenticate a user. This can be done in a number of
4613 ways, depending on if using the system password file, LDAP or the Samba
4614 specific smbpasswd file. How to do this is outside the scope of this manual.
4617 man page for more information.
4620 .Sy USERSHARE section
4623 man page for all configuration options in case you need to modify any options
4624 to the share afterwards. Do note that any changes done with the
4626 command will be undone if the share is ever unshared (such as at a reboot etc).
4628 .Sh INTERFACE STABILITY
projects / zfs / blob