[LU-11555] warn when mounting ZFS pools without "multihost" enabled

• Type: Improvement
• Resolution: Fixed
• Priority: Major
• Fix Version/s: Lustre 2.13.0, Lustre 2.12.1
• Affects Version/s: Lustre 2.12.0, Lustre 2.10.5
• Assignee: Nathaniel Clark
• Reporter: Andreas Dilger

Description

It would be good to warn when importing a pool that does not have the multihost feature enabled, so that users are aware that their pool is exposed to potential data loss in case of double import.

Ideally, this message would only be printed in the case that the OST is configured to be multi-homed (-failnode or -servicenode configured), but it isn't clear that the configuration layer that understands peers knows the pool is ZFS and vice versa. Since we enable multihost for all new pools since 2.10.1 there will hopefully be a relatively smaller number of sites not using this feature. It is not harmful (though not useful) if it is enabled for ZFS 0.6.x, so it might be worthwhile to print a slightly different message for ZFS 0.6.x encouraging the system to be upgraded.

Comments

[Gerrit Updater]

Oleg Drokin ([e-mail]) merged in patch https://review.whamcloud.com/34300/
Subject: LU-11555 utils: ZFS check multihost enabled in read_ldd()
Project: fs/lustre-release
Branch: b2_12
Current Patch Set:
Commit: af58b117ec0e252de641e05722768cad95bba44f

[Gerrit Updater]

Minh Diep ([e-mail]) uploaded a new patch: https://review.whamcloud.com/34300
Subject: LU-11555 utils: ZFS check multihost enabled in read_ldd()
Project: fs/lustre-release
Branch: b2_12
Current Patch Set: 1
Commit: 5ca3ada4555390fcd8b281a3f74ab4475a04a7cd

[Peter Jones]

Landed for 2.13

[Andreas Dilger]

Probably good to include in 2.12.

[Nathaniel Clark]

Should this be ported to 2.10.x and/or 2.12.x?

[Gerrit Updater]

Oleg Drokin ([e-mail]) merged in patch https://review.whamcloud.com/33491/
Subject: LU-11555 utils: ZFS check multihost enabled in read_ldd()
Project: fs/lustre-release
Branch: master
Current Patch Set:
Commit: 5e62552e7fc6e9da4068bb29f62eb2cf7a42970e

[Gerrit Updater]

Nathaniel Clark ([e-mail]) uploaded a new patch: https://review.whamcloud.com/33491
Subject: LU-11555 utils: ZFS check multihost enabled in read_ldd()
Project: fs/lustre-release
Branch: master
Current Patch Set: 1
Commit: 5c645d5a9726f67f9fec0a9b0d4d73f8bda8bc44

[Nathaniel Clark]

There's not a good way to do that on import, but we could probably do it on mount.