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

• Type: Bug
• Resolution: Cannot Reproduce
• Priority: Critical
• Affects Version/s: Lustre 2.10.1
• Labels: zfs
• Environment: trevis
• Severity: 3
• Assignee: Nathaniel Clark
• Reporter: James Casper (Inactive)

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 - unable to import zpools