[LU-5923] Master testing: MDT0 not mounting after master downgrade to 2.5

• Type: Bug
• Resolution: Duplicate
• Priority: Critical
• Environment: File system running 2.5.2 (CentOS 6.5 servers), started with master (most recent commit Ie7a2a98be8cc97db9af7a64476c06fc7321544eb, http://review.whamcloud.com/12142), went back to 2.5.2.
• Severity: 3
• Assignee: WC Triage
• Reporter: Patrick Farrell (Inactive)

Description

After moving a file system running 2.5.2 to master and then moving back, we are unable to mount MDT0:

LustreError: 3262:0:(lfsck_namespace.c:147:lfsck_namespace_load()) perses1-MDT0000-: fail to load lfsck_namespace, expected = 256, rc = -34
LustreError: 3262:0:(mdd_device.c:970:mdd_prepare()) perses1-MDD0000: failed to initialize lfsck: rc = -34
LustreError: 3262:0:(mdt_handler.c:6264:mdt_iocontrol()) perses1-MDT0000: Aborting recovery for device
LustreError: 3262:0:(obd_mount_server.c:1739:server_fill_super()) Unable to start targets: -34

I've already tried a write_conf, which didn't change anything.

If anyone has an idea of the root cause or how to resolve this for the active file system, I'd appreciate the input, as it's down at the moment.

Issue Links

• duplicates: LU-5707 LFSCK 3: cannot load namespace LFSCK tracing file after downgrade from Lustre-2.7
• is duplicated by: LU-5707 LFSCK 3: cannot load namespace LFSCK tracing file after downgrade from Lustre-2.7