[LU-16146] after dropping mgs/mdt0 for test: mdt_handler.c:7522:mdt_postrecov()) lflood-MDT0000: auto trigger paused LFSCK failed: rc = -6

• Status: Closed
• Project: Lustre
• Affects Version/s: Lustre 2.15.0
• Type: Bug
• Priority: Major
• Reporter: Gian-Carlo Defazio
• Assignee: Lai Siyao
• Resolution: Cannot Reproduce
• Labels: llnl

Environment

TOSS 4.4-4.1
4.18.0-372.19.1.1toss.t4.x86_64
lustre 2.15.0_3.llnl

• Severity: 3

Description

After doing a test that involved turning off the mgs/mdt0 node for the test cluster garter, the mdts fail to come back up.  They are stuck "WAITING".

When the mgs node was powered off, an ior test was in progress.

Failover seemed to work, but the ior job was unable to finish. The cluster was eventually rebooted.

After the reboot, the logs show that all 4 mdts are failing an lfsck_start with a line such as

2022-09-07 14:35:12 [ 5791.188613] Lustre: 32474:0:(mdt_handler.c:7522:mdt_postrecov()) lflood-MDT0000: auto trigger paused LFSCK failed: rc = -6

I believe that -6 is coming from lfsck_start()

        lfsck = lfsck_instance_find(key, true, false);                                                           
        if (unlikely(lfsck == NULL))                                                                             
                RETURN(-ENXIO);                                                                                  
                                                                                                                 
        if (unlikely(lfsck->li_stopping))                                                                        
                GOTO(put, rc = -ENXIO); 

For our reference, our local ticket is TOSS5875

Comments

[Peter Jones]

Lai

Could you please advise on this one?

Thanks

Peter

[Olaf Faaland]

Gian-Carlo,

Can you describe what you saw that gave the impression that "Failover seemed to work"?   IE did the mgs and mdts mount, but never exit recovery?  And I think attach the console log for the garter nodes that were hosting the MGS and MDT0000 at any point during this sequence of events.

thanks

[Gian-Carlo Defazio]

For the failover, I could see pacemaker moving MGS and MDT0 from garter1 to garter2 after garter1 was turned off, then ltop showed MDT1 running on garter2.

[Gian-Carlo Defazio]

I've added the console logs for garter[1,2]

[Lai Siyao]

I'll review related code. It's better if you can enable trace with "lfs set_param debug=+trace" and dump debug of MDS.

[Peter Jones]

defazio will you be able to gather this additional debug info?

[Gian-Carlo Defazio]

pjones
Sorry for the delay.
The system I'd need to generate those logs on, garter, is being used for higher priority stuff right now. It's using new MDTs and OSTs. I have the old MDTs that failed on lfsck_start saved, but I can't switch back to them right now.

So yes I can get logs for trying to start up the MDTs, but I'm not sure when.

[Gian-Carlo Defazio]

We were unable to reproduce this when bringing up out file system both manually and using pacemaker.