[LU-3357] lctl replace_nids loses Target UUID from llog header

• Type: Bug
• Resolution: Fixed
• Priority: Critical
• Fix Version/s: Lustre 2.5.0
• Affects Version/s: Lustre 2.4.0
• Severity: 3
• Assignee: Nathaniel Clark
• Reporter: Nathaniel Clark

Description

This is reproducible using master (circa tag 2.4.50)

Prior to replace nids:

[root@lumgr1 CONFIGS]# llog_reader t32fs-client
Header size : 8192
Time : Thu Feb  7 22:24:35 2013
Number of records: 35
Target uuid : config_uuid 
-----------------------
...

After remounting w/ nosvc and running:
lctl replace_nids t32fs-OST0000 192.168.139.20@tcp

same log files is now:

Header size : 8192
Time : Mon May 20 09:13:03 2013
Number of records: 35
Target uuid :  
-----------------------
...

The "Target uuid" is also deleted from t32fs-MDT0000.

I used conf-sanity/32 tarball disk2_1-ldiskfs.tar.bz2 as my starting point.

Issue Links

• is blocking: LU-2200 Test failure on test suite conf-sanity, subtest test_32a

Comments

[Nathaniel Clark]

Patch merged to master (post 2.4.51)

[Mikhail Pershin]

OK, got it.

[Nathaniel Clark]

Mike,

This field doesn't seem to be used too often, but it is checked in the lctl conf_param code path, and if it's not set correctly, the conf_param fails (see llog_init_handle) in MDS debug_log in https://maloo.whamcloud.com/test_sets/8391fe9a-c0cf-11e2-8490-52540035b04c

[Mikhail Pershin]

I wonder is that so critical to see that UUID? I find it useless, we know already that this is config llog, just because of name. Is it really helpful for something or used by some other tool?

[Nathaniel Clark]

http://review.whamcloud.com/6395