[LU-5202] LFSCK 5: LFSCK needs to log all changes and errors found

• Type: Improvement
• Resolution: Unresolved
• Priority: Major
• Affects Version/s: Lustre 2.6.0, Lustre 2.5.5
• Labels: mq115
• Assignee: WC Triage
• Reporter: Andreas Dilger

Description

LFSCK needs to log with D_LFSCK all fixes that it makes and any inconsistencies that it finds that it does not repair (e.g. unknown LOV magic layouts). Otherwise it will be making secret changes to the filesystem and when there are problems they will be impossible to debug.

There should be a mechanism for logging D_LFSCK messages to a separate log file for administrators to review, so that the kernel debug messages are not lost. A simple mechanism would be debug_daemon to log all messages to a file, then "lctl filter all; lctl show lfsck" (or similar) to filter all except lfsck messages into a text log file.

The problem with this approach is that debug_daemon will consume all debug messages while it is running, and it will log a lot more than just D_LFSCK messages to disk. We may want to consider some other logging mechanism to capture just the D_LFSCK messages.

Issue Links

• is duplicated by: LU-8169 More extensive and accessible logging of lfsck
• is related to: LU-6102 OI scrub is triggered during racer test
• is related to: LU-4610 LFSCK needs to log all changes and errors found