LLOG_READER(8)

NAME
llog_reader - lustre on-disk log parsing utility

SYNOPSIS
llog_reader FILENAME

DESCRIPTION
llog_reader parses the binary format of Lustre's on-disk configuration logs. It can only read the logs. Use tunefs.lustre to write to them.

CAVEATS
Although they are stored in the CONFIGS directory, mountdata files do not use the config log format and will confuse llog_reader.

EXAMPLES
To examine a log file on a stopped Lustre server, first mount its backing file system as ldiskfs, then use llog_reader to dump the log file's contents:
        # mount -t ldiskfs /dev/sda /mnt/mgs
        llog_reader /mnt/mgs/CONFIGS/tfs-client

To examine the same log file on a running Lustre server, use the ldiskfs-enabled debugfs utility (called debug.ldiskfs on some distros) to extract the file:
        # debugfs -c -R 'dump CONFIGS/tfs-client /tmp/tfs-client' /dev/sda
        llog_reader /tmp/tfs-client

To examine Changelog records on a stopped Lustre server, first mount its backing file system as ldiskfs, then use llog_reader to dump the log changelog's contents:
        # 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 :
        -----------------------
        #01 (064)id=[0x5:0x1:0x0]:0 path=
        O/1/d5/5
        # llog_reader /mnt/mgs/
        O/1/d5/5
        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

AVAILABILITY
llog_reader is part of the lustre(7) filesystem package since release 1.4.0

SEE ALSO
lustre(7), tunefs.lustre(8)

Lustre Operations Manual, Troubleshooting Lustre.