[LU-10016] Downgrading Lustre 2.10.1 ZFS to 2.9.0 ZFS gives a pool cannot be found error on import

• Status: Closed
• Project: Lustre
• Affects Version/s: Lustre 2.10.1
• Type: Bug
• Priority: Critical
• Reporter: James Casper
• Assignee: Nathaniel Clark
• Resolution: Cannot Reproduce
• Labels: zfs

Environment

trevis

• Severity: 3

Description

May be related to LU-9960. It fixed the "can't import into ZFS 6.5.7 because a 7.1 feature is installed" issue.

Two downgrade tests:
Downgrade 2.10.1 to 2.10.0: zfs 7.1 to zfs 6.5.9 - works
Downgrade 2.10.1 to 2.9.0: zfs 7.1 to zfs 6.5.7 - pool not found

Pool not found is seen with zpool import <pool name> and zpool import <pool GUID>.

Issue Links

• is related to: LU-9960 Rolling downgrade master to 2.10 - un...

Comments

[Peter Jones]

Nathaniel

Could you please advise?

Thanks

Peter

[Andreas Dilger]

James, do you have more information about the errors printed when this problem happens?

[James Casper]

[root@trevis-62 ~]# zpool import -f 11022747677743727868
cannot import '11022747677743727868': no such pool available

[Nathaniel Clark]

Can you show a bare zfs import from trevis-62 (via ZFS 0.6.5.7)?

I assume this is Lustre 2.10.1-RC1 (so with the LU-9960 patch).

[James Casper]

I'm running another upgrade/downgrade test now (EE3 --> 2.10.1 --> EE3). EE3 also uses 6.5.7 ZFS, so if I don't see this issue there, I'll retest 2.9.0 --> 2.10.1 --> 2.9.0.

[James Casper]

Downgrade from 2.10.1 to EE3 passed. Retesting 2.10.1 to 2.9.0. Will close on Monday if that passes.

[James Casper]

Also passed in a 2.10.1 to 2.9.0 retest. Most likely user error. Closing.