From a13e325130d60b2bec46f67517fa46892e368337 Mon Sep 17 00:00:00 2001 From: Sebastien Buisson Date: Tue, 23 Jan 2018 02:07:01 +0900 Subject: [PATCH] LU-9727 doc: update llog_reader man page for Changelogs Add new paragraph in llog_reader's man page to explain how to read Changelogs with llog_reader, and add an example. Test-Parameters: trivial Signed-off-by: Sebastien Buisson Change-Id: I3e1123b9a5ac88334a370fd69c1d9d63597e16f7 Reviewed-on: https://review.whamcloud.com/30970 Reviewed-by: Andreas Dilger Reviewed-by: Olaf Weber Tested-by: Jenkins Tested-by: Maloo Reviewed-by: Oleg Drokin --- lustre/doc/llog_reader.8 | 35 +++++++++++++++++++++++++++++++++++ 1 file changed, 35 insertions(+) diff --git a/lustre/doc/llog_reader.8 b/lustre/doc/llog_reader.8 index b77542c..d1fc26c 100644 --- a/lustre/doc/llog_reader.8 +++ b/lustre/doc/llog_reader.8 @@ -30,6 +30,41 @@ on some distros) to extract the file, e.g. debugfs -c -R 'dump CONFIGS/tfs-client /tmp/tfs-client' /dev/sda llog_reader /tmp/tfs-client .fi +.LP +To examine Changelog records on a stopped Lustre server, first mount its +backing file system as ldiskfs, then use +.B llog_reader +to dump the log changelog's contents, e.g. +.IP +.nf +# mount -t ldiskfs /dev/sda /mnt/mgs +# llog_reader /mnt/mgs/changelog_catalog +rec #1 type=1064553b len=64 offset 8192 +Header size : 8192 +Time : Mon Jan 22 23:28:24 2018 +Number of records: 1 +Target uuid : +----------------------- +.fi +#01 (064)id=[0x5:0x1:0x0]:0 path= +.B "O/1/d5/5" + +# llog_reader /mnt/mgs/ +.B O/1/d5/5 +.nf +rec #1 type=10660000 len=136 offset 8192 +rec #2 type=10660000 len=136 offset 8328 +rec #3 type=10660000 len=128 offset 8464 +Header size : 8192 +Time : Mon Jan 22 23:30:01 2018 +Number of records: 3 +Target uuid : +----------------------- +#01 (136)changelog record id:0x0 cr_flags:0x9000 cr_type:CREAT(0x1) +date:'14:30:01.370700741 2018.01.22' target:[0x200000402:0x1:0x0] +cr_extra_flags:0x3 user:0:0 nid:10.128.11.159@tcp parent:[0x200000007:0x1:0x0] +name:fileA +.fi .SH CAVEATS Although they are stored in the CONFIGS directory, \fImountdata\fR files do not use the config log format and will confuse \fBllog_reader\fR. -- 1.8.3.1