From cae97c88c4ed2d99b523b84c713993d26034a23b Mon Sep 17 00:00:00 2001 From: Serapheim Dimitropoulos Date: Wed, 31 Jul 2019 09:29:01 -0700 Subject: [PATCH] List log_spacemap feature in zpool-features.5 manual Update zpool-features.5 manpage to describe the log_spacemap feature. Reviewed-by: Matthew Ahrens Reviewed-by: Brian Behlendorf Reviewed-by: Pavel Zakharov Signed-off-by: Serapheim Dimitropoulos Closes #9096 --- man/man5/zpool-features.5 | 22 ++++++++++++++++++++++ 1 file changed, 22 insertions(+) diff --git a/man/man5/zpool-features.5 b/man/man5/zpool-features.5 index 00bad9f74..6c03f9049 100644 --- a/man/man5/zpool-features.5 +++ b/man/man5/zpool-features.5 @@ -567,6 +567,28 @@ The feature is activated when a clone is created and remains active until all clones have been destroyed. .RE +.sp +.ne 2 +.na +\fBlog_spacemap\fR +.ad +.RS 4n +.TS +l l . +GUID com.delphix:log_spacemap +READ\-ONLY COMPATIBLE yes +DEPENDENCIES com.delphix:spacemap_v2 +.TE + +This feature improves performance for heavily-fragmented pools, +especially when workloads are heavy in random-writes. It does so by +logging all the metaslab changes on a single spacemap every TXG +instead of scattering multiple writes to all the metaslab spacemaps. + +This feature becomes \fBactive\fR as soon as it is enabled and will never +return to being \fBenabled\fR. +.RE + .sp .ne 2 .na -- 2.40.0