1 /*-------------------------------------------------------------------------
4 * A utility to "zero out" the xlog when it's corrupt beyond recovery.
5 * Can also rebuild pg_control if needed.
7 * The theory of operation is fairly simple:
8 * 1. Read the existing pg_control (which will include the last
9 * checkpoint record). If it is an old format then update to
11 * 2. If pg_control is corrupt, attempt to intuit reasonable values,
12 * by scanning the old xlog if necessary.
13 * 3. Modify pg_control to reflect a "shutdown" state with a checkpoint
14 * record at the start of xlog.
15 * 4. Flush the existing xlog files and write a new segment with
16 * just a checkpoint record in it. The new segment is positioned
17 * just past the end of the old xlog, so that existing LSNs in
18 * data pages will appear to be "in the past".
19 * This is all pretty straightforward except for the intuition part of
23 * Portions Copyright (c) 1996-2009, PostgreSQL Global Development Group
24 * Portions Copyright (c) 1994, Regents of the University of California
26 * $PostgreSQL: pgsql/src/bin/pg_resetxlog/pg_resetxlog.c,v 1.71 2009/01/01 17:23:54 momjian Exp $
28 *-------------------------------------------------------------------------
32 * We have to use postgres.h not postgres_fe.h here, because there's so much
33 * backend-only stuff in the XLOG include files we need. But we need a
34 * frontend-ish environment otherwise. Hence this ugly hack.
51 #include "access/transam.h"
52 #include "access/tuptoaster.h"
53 #include "access/multixact.h"
54 #include "access/xlog_internal.h"
55 #include "catalog/catversion.h"
56 #include "catalog/pg_control.h"
62 static ControlFileData ControlFile; /* pg_control values */
63 static uint32 newXlogId,
64 newXlogSeg; /* ID/Segment of new XLOG segment */
65 static bool guessed = false; /* T if we had to guess at any values */
66 static const char *progname;
68 static bool ReadControlFile(void);
69 static void GuessControlValues(void);
70 static void PrintControlValues(bool guessed);
71 static void RewriteControlFile(void);
72 static void FindEndOfXLOG(void);
73 static void KillExistingXLOG(void);
74 static void WriteEmptyXLOG(void);
75 static void usage(void);
79 main(int argc, char *argv[])
83 bool noupdate = false;
84 uint32 set_xid_epoch = (uint32) -1;
85 TransactionId set_xid = 0;
87 MultiXactId set_mxid = 0;
88 MultiXactOffset set_mxoff = (MultiXactOffset) -1;
89 uint32 minXlogTli = 0,
99 set_pglocale_pgservice(argv[0], PG_TEXTDOMAIN("pg_resetxlog"));
101 progname = get_progname(argv[0]);
105 if (strcmp(argv[1], "--help") == 0 || strcmp(argv[1], "-?") == 0)
110 if (strcmp(argv[1], "--version") == 0 || strcmp(argv[1], "-V") == 0)
112 puts("pg_resetxlog (PostgreSQL) " PG_VERSION);
118 while ((c = getopt(argc, argv, "fl:m:no:O:x:e:")) != -1)
131 set_xid_epoch = strtoul(optarg, &endptr, 0);
132 if (endptr == optarg || *endptr != '\0')
134 fprintf(stderr, _("%s: invalid argument for option -e\n"), progname);
135 fprintf(stderr, _("Try \"%s --help\" for more information.\n"), progname);
138 if (set_xid_epoch == -1)
140 fprintf(stderr, _("%s: transaction ID epoch (-e) must not be -1\n"), progname);
146 set_xid = strtoul(optarg, &endptr, 0);
147 if (endptr == optarg || *endptr != '\0')
149 fprintf(stderr, _("%s: invalid argument for option -x\n"), progname);
150 fprintf(stderr, _("Try \"%s --help\" for more information.\n"), progname);
155 fprintf(stderr, _("%s: transaction ID (-x) must not be 0\n"), progname);
161 set_oid = strtoul(optarg, &endptr, 0);
162 if (endptr == optarg || *endptr != '\0')
164 fprintf(stderr, _("%s: invalid argument for option -o\n"), progname);
165 fprintf(stderr, _("Try \"%s --help\" for more information.\n"), progname);
170 fprintf(stderr, _("%s: OID (-o) must not be 0\n"), progname);
176 set_mxid = strtoul(optarg, &endptr, 0);
177 if (endptr == optarg || *endptr != '\0')
179 fprintf(stderr, _("%s: invalid argument for option -m\n"), progname);
180 fprintf(stderr, _("Try \"%s --help\" for more information.\n"), progname);
185 fprintf(stderr, _("%s: multitransaction ID (-m) must not be 0\n"), progname);
191 set_mxoff = strtoul(optarg, &endptr, 0);
192 if (endptr == optarg || *endptr != '\0')
194 fprintf(stderr, _("%s: invalid argument for option -O\n"), progname);
195 fprintf(stderr, _("Try \"%s --help\" for more information.\n"), progname);
200 fprintf(stderr, _("%s: multitransaction offset (-O) must not be -1\n"), progname);
206 minXlogTli = strtoul(optarg, &endptr, 0);
207 if (endptr == optarg || *endptr != ',')
209 fprintf(stderr, _("%s: invalid argument for option -l\n"), progname);
210 fprintf(stderr, _("Try \"%s --help\" for more information.\n"), progname);
213 minXlogId = strtoul(endptr + 1, &endptr2, 0);
214 if (endptr2 == endptr + 1 || *endptr2 != ',')
216 fprintf(stderr, _("%s: invalid argument for option -l\n"), progname);
217 fprintf(stderr, _("Try \"%s --help\" for more information.\n"), progname);
220 minXlogSeg = strtoul(endptr2 + 1, &endptr3, 0);
221 if (endptr3 == endptr2 + 1 || *endptr3 != '\0')
223 fprintf(stderr, _("%s: invalid argument for option -l\n"), progname);
224 fprintf(stderr, _("Try \"%s --help\" for more information.\n"), progname);
230 fprintf(stderr, _("Try \"%s --help\" for more information.\n"), progname);
237 fprintf(stderr, _("%s: no data directory specified\n"), progname);
238 fprintf(stderr, _("Try \"%s --help\" for more information.\n"), progname);
243 * Don't allow pg_resetxlog to be run as root, to avoid overwriting the
244 * ownership of files in the data directory. We need only check for root
245 * -- any other user won't have sufficient permissions to modify files in
246 * the data directory.
251 fprintf(stderr, _("%s: cannot be executed by \"root\"\n"),
253 fprintf(stderr, _("You must run %s as the PostgreSQL superuser.\n"),
259 DataDir = argv[optind];
261 if (chdir(DataDir) < 0)
263 fprintf(stderr, _("%s: could not change directory to \"%s\": %s\n"),
264 progname, DataDir, strerror(errno));
269 * Check for a postmaster lock file --- if there is one, refuse to
270 * proceed, on grounds we might be interfering with a live installation.
272 snprintf(path, MAXPGPATH, "%s/postmaster.pid", DataDir);
274 if ((fd = open(path, O_RDONLY, 0)) < 0)
278 fprintf(stderr, _("%s: could not open file \"%s\" for reading: %s\n"), progname, path, strerror(errno));
284 fprintf(stderr, _("%s: lock file \"%s\" exists\n"
285 "Is a server running? If not, delete the lock file and try again.\n"),
291 * Attempt to read the existing pg_control file
293 if (!ReadControlFile())
294 GuessControlValues();
297 * Also look at existing segment files to set up newXlogId/newXlogSeg
302 * Adjust fields if required by switches. (Do this now so that printout,
303 * if any, includes these values.)
305 if (set_xid_epoch != -1)
306 ControlFile.checkPointCopy.nextXidEpoch = set_xid_epoch;
309 ControlFile.checkPointCopy.nextXid = set_xid;
312 ControlFile.checkPointCopy.nextOid = set_oid;
315 ControlFile.checkPointCopy.nextMulti = set_mxid;
318 ControlFile.checkPointCopy.nextMultiOffset = set_mxoff;
320 if (minXlogTli > ControlFile.checkPointCopy.ThisTimeLineID)
321 ControlFile.checkPointCopy.ThisTimeLineID = minXlogTli;
323 if (minXlogId > newXlogId ||
324 (minXlogId == newXlogId &&
325 minXlogSeg > newXlogSeg))
327 newXlogId = minXlogId;
328 newXlogSeg = minXlogSeg;
332 * If we had to guess anything, and -f was not given, just print the
333 * guessed values and exit. Also print if -n is given.
335 if ((guessed && !force) || noupdate)
337 PrintControlValues(guessed);
340 printf(_("\nIf these values seem acceptable, use -f to force reset.\n"));
348 * Don't reset from a dirty pg_control without -f, either.
350 if (ControlFile.state != DB_SHUTDOWNED && !force)
352 printf(_("The database server was not shut down cleanly.\n"
353 "Resetting the transaction log might cause data to be lost.\n"
354 "If you want to proceed anyway, use -f to force reset.\n"));
359 * Else, do the dirty deed.
361 RewriteControlFile();
365 printf(_("Transaction log reset\n"));
371 * Try to read the existing pg_control file.
373 * This routine is also responsible for updating old pg_control versions
374 * to the current format. (Currently we don't do anything of the sort.)
377 ReadControlFile(void)
384 if ((fd = open(XLOG_CONTROL_FILE, O_RDONLY | PG_BINARY, 0)) < 0)
387 * If pg_control is not there at all, or we can't read it, the odds
388 * are we've been handed a bad DataDir path, so give up. User can do
389 * "touch pg_control" to force us to proceed.
391 fprintf(stderr, _("%s: could not open file \"%s\" for reading: %s\n"),
392 progname, XLOG_CONTROL_FILE, strerror(errno));
394 fprintf(stderr, _("If you are sure the data directory path is correct, execute\n"
401 /* Use malloc to ensure we have a maxaligned buffer */
402 buffer = (char *) malloc(PG_CONTROL_SIZE);
404 len = read(fd, buffer, PG_CONTROL_SIZE);
407 fprintf(stderr, _("%s: could not read file \"%s\": %s\n"),
408 progname, XLOG_CONTROL_FILE, strerror(errno));
413 if (len >= sizeof(ControlFileData) &&
414 ((ControlFileData *) buffer)->pg_control_version == PG_CONTROL_VERSION)
420 offsetof(ControlFileData, crc));
423 if (EQ_CRC32(crc, ((ControlFileData *) buffer)->crc))
426 memcpy(&ControlFile, buffer, sizeof(ControlFile));
430 fprintf(stderr, _("%s: pg_control exists but has invalid CRC; proceed with caution\n"),
432 /* We will use the data anyway, but treat it as guessed. */
433 memcpy(&ControlFile, buffer, sizeof(ControlFile));
438 /* Looks like it's a mess. */
439 fprintf(stderr, _("%s: pg_control exists but is broken or unknown version; ignoring it\n"),
446 * Guess at pg_control values when we can't read the old ones.
449 GuessControlValues(void)
451 uint64 sysidentifier;
455 * Set up a completely default set of pg_control values.
458 memset(&ControlFile, 0, sizeof(ControlFile));
460 ControlFile.pg_control_version = PG_CONTROL_VERSION;
461 ControlFile.catalog_version_no = CATALOG_VERSION_NO;
464 * Create a new unique installation identifier, since we can no longer use
465 * any old XLOG records. See notes in xlog.c about the algorithm.
467 gettimeofday(&tv, NULL);
468 sysidentifier = ((uint64) tv.tv_sec) << 32;
469 sysidentifier |= (uint32) (tv.tv_sec | tv.tv_usec);
471 ControlFile.system_identifier = sysidentifier;
473 ControlFile.checkPointCopy.redo.xlogid = 0;
474 ControlFile.checkPointCopy.redo.xrecoff = SizeOfXLogLongPHD;
475 ControlFile.checkPointCopy.ThisTimeLineID = 1;
476 ControlFile.checkPointCopy.nextXidEpoch = 0;
477 ControlFile.checkPointCopy.nextXid = (TransactionId) 514; /* XXX */
478 ControlFile.checkPointCopy.nextOid = FirstBootstrapObjectId;
479 ControlFile.checkPointCopy.nextMulti = FirstMultiXactId;
480 ControlFile.checkPointCopy.nextMultiOffset = 0;
481 ControlFile.checkPointCopy.time = (pg_time_t) time(NULL);
483 ControlFile.state = DB_SHUTDOWNED;
484 ControlFile.time = (pg_time_t) time(NULL);
485 ControlFile.checkPoint = ControlFile.checkPointCopy.redo;
487 ControlFile.maxAlign = MAXIMUM_ALIGNOF;
488 ControlFile.floatFormat = FLOATFORMAT_VALUE;
489 ControlFile.blcksz = BLCKSZ;
490 ControlFile.relseg_size = RELSEG_SIZE;
491 ControlFile.xlog_blcksz = XLOG_BLCKSZ;
492 ControlFile.xlog_seg_size = XLOG_SEG_SIZE;
493 ControlFile.nameDataLen = NAMEDATALEN;
494 ControlFile.indexMaxKeys = INDEX_MAX_KEYS;
495 ControlFile.toast_max_chunk_size = TOAST_MAX_CHUNK_SIZE;
496 #ifdef HAVE_INT64_TIMESTAMP
497 ControlFile.enableIntTimes = true;
499 ControlFile.enableIntTimes = false;
501 ControlFile.float4ByVal = FLOAT4PASSBYVAL;
502 ControlFile.float8ByVal = FLOAT8PASSBYVAL;
505 * XXX eventually, should try to grovel through old XLOG to develop more
506 * accurate values for TimeLineID, nextXID, etc.
512 * Print the guessed pg_control values when we had to guess.
514 * NB: this display should be just those fields that will not be
515 * reset by RewriteControlFile().
518 PrintControlValues(bool guessed)
520 char sysident_str[32];
523 printf(_("Guessed pg_control values:\n\n"));
525 printf(_("pg_control values:\n\n"));
528 * Format system_identifier separately to keep platform-dependent format
529 * code out of the translatable message string.
531 snprintf(sysident_str, sizeof(sysident_str), UINT64_FORMAT,
532 ControlFile.system_identifier);
534 printf(_("First log file ID after reset: %u\n"),
536 printf(_("First log file segment after reset: %u\n"),
538 printf(_("pg_control version number: %u\n"),
539 ControlFile.pg_control_version);
540 printf(_("Catalog version number: %u\n"),
541 ControlFile.catalog_version_no);
542 printf(_("Database system identifier: %s\n"),
544 printf(_("Latest checkpoint's TimeLineID: %u\n"),
545 ControlFile.checkPointCopy.ThisTimeLineID);
546 printf(_("Latest checkpoint's NextXID: %u/%u\n"),
547 ControlFile.checkPointCopy.nextXidEpoch,
548 ControlFile.checkPointCopy.nextXid);
549 printf(_("Latest checkpoint's NextOID: %u\n"),
550 ControlFile.checkPointCopy.nextOid);
551 printf(_("Latest checkpoint's NextMultiXactId: %u\n"),
552 ControlFile.checkPointCopy.nextMulti);
553 printf(_("Latest checkpoint's NextMultiOffset: %u\n"),
554 ControlFile.checkPointCopy.nextMultiOffset);
555 printf(_("Maximum data alignment: %u\n"),
556 ControlFile.maxAlign);
557 /* we don't print floatFormat since can't say much useful about it */
558 printf(_("Database block size: %u\n"),
560 printf(_("Blocks per segment of large relation: %u\n"),
561 ControlFile.relseg_size);
562 printf(_("WAL block size: %u\n"),
563 ControlFile.xlog_blcksz);
564 printf(_("Bytes per WAL segment: %u\n"),
565 ControlFile.xlog_seg_size);
566 printf(_("Maximum length of identifiers: %u\n"),
567 ControlFile.nameDataLen);
568 printf(_("Maximum columns in an index: %u\n"),
569 ControlFile.indexMaxKeys);
570 printf(_("Maximum size of a TOAST chunk: %u\n"),
571 ControlFile.toast_max_chunk_size);
572 printf(_("Date/time type storage: %s\n"),
573 (ControlFile.enableIntTimes ? _("64-bit integers") : _("floating-point numbers")));
574 printf(_("Float4 argument passing: %s\n"),
575 (ControlFile.float4ByVal ? _("by value") : _("by reference")));
576 printf(_("Float8 argument passing: %s\n"),
577 (ControlFile.float8ByVal ? _("by value") : _("by reference")));
582 * Write out the new pg_control file.
585 RewriteControlFile(void)
588 char buffer[PG_CONTROL_SIZE]; /* need not be aligned */
591 * Adjust fields as needed to force an empty XLOG starting at
592 * newXlogId/newXlogSeg.
594 ControlFile.checkPointCopy.redo.xlogid = newXlogId;
595 ControlFile.checkPointCopy.redo.xrecoff =
596 newXlogSeg * XLogSegSize + SizeOfXLogLongPHD;
597 ControlFile.checkPointCopy.time = (pg_time_t) time(NULL);
599 ControlFile.state = DB_SHUTDOWNED;
600 ControlFile.time = (pg_time_t) time(NULL);
601 ControlFile.checkPoint = ControlFile.checkPointCopy.redo;
602 ControlFile.prevCheckPoint.xlogid = 0;
603 ControlFile.prevCheckPoint.xrecoff = 0;
604 ControlFile.minRecoveryPoint.xlogid = 0;
605 ControlFile.minRecoveryPoint.xrecoff = 0;
607 /* Now we can force the recorded xlog seg size to the right thing. */
608 ControlFile.xlog_seg_size = XLogSegSize;
610 /* Contents are protected with a CRC */
611 INIT_CRC32(ControlFile.crc);
612 COMP_CRC32(ControlFile.crc,
613 (char *) &ControlFile,
614 offsetof(ControlFileData, crc));
615 FIN_CRC32(ControlFile.crc);
618 * We write out PG_CONTROL_SIZE bytes into pg_control, zero-padding the
619 * excess over sizeof(ControlFileData). This reduces the odds of
620 * premature-EOF errors when reading pg_control. We'll still fail when we
621 * check the contents of the file, but hopefully with a more specific
622 * error than "couldn't read pg_control".
624 if (sizeof(ControlFileData) > PG_CONTROL_SIZE)
627 _("%s: internal error -- sizeof(ControlFileData) is too large ... fix PG_CONTROL_SIZE\n"),
632 memset(buffer, 0, PG_CONTROL_SIZE);
633 memcpy(buffer, &ControlFile, sizeof(ControlFileData));
635 unlink(XLOG_CONTROL_FILE);
637 fd = open(XLOG_CONTROL_FILE,
638 O_RDWR | O_CREAT | O_EXCL | PG_BINARY,
642 fprintf(stderr, _("%s: could not create pg_control file: %s\n"),
643 progname, strerror(errno));
648 if (write(fd, buffer, PG_CONTROL_SIZE) != PG_CONTROL_SIZE)
650 /* if write didn't set errno, assume problem is no disk space */
653 fprintf(stderr, _("%s: could not write pg_control file: %s\n"),
654 progname, strerror(errno));
660 fprintf(stderr, _("%s: fsync error: %s\n"), progname, strerror(errno));
669 * Scan existing XLOG files and determine the highest existing WAL address
671 * On entry, ControlFile.checkPointCopy.redo and ControlFile.xlog_seg_size
672 * are assumed valid (note that we allow the old xlog seg size to differ
673 * from what we're using). On exit, newXlogId and newXlogSeg are set to
674 * suitable values for the beginning of replacement WAL (in our seg size).
683 * Initialize the max() computation using the last checkpoint address from
684 * old pg_control. Note that for the moment we are working with segment
685 * numbering according to the old xlog seg size.
687 newXlogId = ControlFile.checkPointCopy.redo.xlogid;
688 newXlogSeg = ControlFile.checkPointCopy.redo.xrecoff / ControlFile.xlog_seg_size;
691 * Scan the pg_xlog directory to find existing WAL segment files. We
692 * assume any present have been used; in most scenarios this should be
693 * conservative, because of xlog.c's attempts to pre-create files.
695 xldir = opendir(XLOGDIR);
698 fprintf(stderr, _("%s: could not open directory \"%s\": %s\n"),
699 progname, XLOGDIR, strerror(errno));
704 while ((xlde = readdir(xldir)) != NULL)
706 if (strlen(xlde->d_name) == 24 &&
707 strspn(xlde->d_name, "0123456789ABCDEF") == 24)
713 sscanf(xlde->d_name, "%08X%08X%08X", &tli, &log, &seg);
716 * Note: we take the max of all files found, regardless of their
717 * timelines. Another possibility would be to ignore files of
718 * timelines other than the target TLI, but this seems safer.
719 * Better too large a result than too small...
721 if (log > newXlogId ||
722 (log == newXlogId && seg > newXlogSeg))
733 * This fix is in mingw cvs (runtime/mingwex/dirent.c rev 1.4), but not in
736 if (GetLastError() == ERROR_NO_MORE_FILES)
742 fprintf(stderr, _("%s: could not read from directory \"%s\": %s\n"),
743 progname, XLOGDIR, strerror(errno));
749 * Finally, convert to new xlog seg size, and advance by one to ensure we
750 * are in virgin territory.
752 newXlogSeg *= ControlFile.xlog_seg_size;
753 newXlogSeg = (newXlogSeg + XLogSegSize - 1) / XLogSegSize;
755 /* be sure we wrap around correctly at end of a logfile */
756 NextLogSeg(newXlogId, newXlogSeg);
761 * Remove existing XLOG files
764 KillExistingXLOG(void)
768 char path[MAXPGPATH];
770 xldir = opendir(XLOGDIR);
773 fprintf(stderr, _("%s: could not open directory \"%s\": %s\n"),
774 progname, XLOGDIR, strerror(errno));
779 while ((xlde = readdir(xldir)) != NULL)
781 if (strlen(xlde->d_name) == 24 &&
782 strspn(xlde->d_name, "0123456789ABCDEF") == 24)
784 snprintf(path, MAXPGPATH, "%s/%s", XLOGDIR, xlde->d_name);
785 if (unlink(path) < 0)
787 fprintf(stderr, _("%s: could not delete file \"%s\": %s\n"),
788 progname, path, strerror(errno));
797 * This fix is in mingw cvs (runtime/mingwex/dirent.c rev 1.4), but not in
800 if (GetLastError() == ERROR_NO_MORE_FILES)
806 fprintf(stderr, _("%s: could not read from directory \"%s\": %s\n"),
807 progname, XLOGDIR, strerror(errno));
815 * Write an empty XLOG file, containing only the checkpoint record
816 * already set up in ControlFile.
823 XLogLongPageHeader longpage;
826 char path[MAXPGPATH];
830 /* Use malloc() to ensure buffer is MAXALIGNED */
831 buffer = (char *) malloc(XLOG_BLCKSZ);
832 page = (XLogPageHeader) buffer;
833 memset(buffer, 0, XLOG_BLCKSZ);
835 /* Set up the XLOG page header */
836 page->xlp_magic = XLOG_PAGE_MAGIC;
837 page->xlp_info = XLP_LONG_HEADER;
838 page->xlp_tli = ControlFile.checkPointCopy.ThisTimeLineID;
839 page->xlp_pageaddr.xlogid =
840 ControlFile.checkPointCopy.redo.xlogid;
841 page->xlp_pageaddr.xrecoff =
842 ControlFile.checkPointCopy.redo.xrecoff - SizeOfXLogLongPHD;
843 longpage = (XLogLongPageHeader) page;
844 longpage->xlp_sysid = ControlFile.system_identifier;
845 longpage->xlp_seg_size = XLogSegSize;
846 longpage->xlp_xlog_blcksz = XLOG_BLCKSZ;
848 /* Insert the initial checkpoint record */
849 record = (XLogRecord *) ((char *) page + SizeOfXLogLongPHD);
850 record->xl_prev.xlogid = 0;
851 record->xl_prev.xrecoff = 0;
852 record->xl_xid = InvalidTransactionId;
853 record->xl_tot_len = SizeOfXLogRecord + sizeof(CheckPoint);
854 record->xl_len = sizeof(CheckPoint);
855 record->xl_info = XLOG_CHECKPOINT_SHUTDOWN;
856 record->xl_rmid = RM_XLOG_ID;
857 memcpy(XLogRecGetData(record), &ControlFile.checkPointCopy,
861 COMP_CRC32(crc, &ControlFile.checkPointCopy, sizeof(CheckPoint));
862 COMP_CRC32(crc, (char *) record + sizeof(pg_crc32),
863 SizeOfXLogRecord - sizeof(pg_crc32));
865 record->xl_crc = crc;
867 /* Write the first page */
868 XLogFilePath(path, ControlFile.checkPointCopy.ThisTimeLineID,
869 newXlogId, newXlogSeg);
873 fd = open(path, O_RDWR | O_CREAT | O_EXCL | PG_BINARY,
877 fprintf(stderr, _("%s: could not open file \"%s\": %s\n"),
878 progname, path, strerror(errno));
883 if (write(fd, buffer, XLOG_BLCKSZ) != XLOG_BLCKSZ)
885 /* if write didn't set errno, assume problem is no disk space */
888 fprintf(stderr, _("%s: could not write file \"%s\": %s\n"),
889 progname, path, strerror(errno));
893 /* Fill the rest of the file with zeroes */
894 memset(buffer, 0, XLOG_BLCKSZ);
895 for (nbytes = XLOG_BLCKSZ; nbytes < XLogSegSize; nbytes += XLOG_BLCKSZ)
898 if (write(fd, buffer, XLOG_BLCKSZ) != XLOG_BLCKSZ)
902 fprintf(stderr, _("%s: could not write file \"%s\": %s\n"),
903 progname, path, strerror(errno));
910 fprintf(stderr, _("%s: fsync error: %s\n"), progname, strerror(errno));
921 printf(_("%s resets the PostgreSQL transaction log.\n\n"), progname);
922 printf(_("Usage:\n %s [OPTION]... DATADIR\n\n"), progname);
923 printf(_("Options:\n"));
924 printf(_(" -f force update to be done\n"));
925 printf(_(" -l TLI,FILE,SEG force minimum WAL starting location for new transaction log\n"));
926 printf(_(" -m XID set next multitransaction ID\n"));
927 printf(_(" -n no update, just show extracted control values (for testing)\n"));
928 printf(_(" -o OID set next OID\n"));
929 printf(_(" -O OFFSET set next multitransaction offset\n"));
930 printf(_(" -x XID set next transaction ID\n"));
931 printf(_(" -e XIDEPOCH set next transaction ID epoch\n"));
932 printf(_(" --help show this help, then exit\n"));
933 printf(_(" --version output version information, then exit\n"));
934 printf(_("\nReport bugs to <pgsql-bugs@postgresql.org>.\n"));