[LU-12530] udev add/change rule loads zfs module on clients

• Type: Bug
• Resolution: Fixed
• Priority: Minor
• Fix Version/s: Lustre 2.14.0, Lustre 2.12.4
• Affects Version/s: Lustre 2.10.5, Lustre 2.12.2
• Severity: 3
• Assignee: Nathaniel Clark
• Reporter: Olaf Faaland

Description

Lustre loads the zfs module whenever a block device is added or changed, if Lustre was built against zfs. It unintentionally does this on clients as well as servers.

Commit 0d11a314787bc795797a016262e9bcfe86e2193e for LU-11563 added a udev rule,
lustre/conf/99-lustre-server.rules

When a block device is added or changed:
udev -> l_tunedisk
l_tunedisk -> mount_utils.c:osd_init()
osd_init() > backfs_ops[]>init() AKA zfs_init()
zfs_init() -> "/sbin/modprobe -q zfs"

This occurs if the Lustre rpms installed are a full build of Lustre, instead of just a client build.

Issue Links

• is related to: LU-10599 Possible for ID_FS_TYPE to be lustre / ldiskfs?
• is related to: LU-9551 I/O errors when lustre uses multipath devices
• is related to: LU-11736 Do not apply bulk IO tuning on MDT or MGT devices

Comments

[Gerrit Updater]

Oleg Drokin ([e-mail]) merged in patch https://review.whamcloud.com/36776/
Subject: LU-12530 utils: narrow l_tunedisk udev rule
Project: fs/lustre-release
Branch: b2_12
Current Patch Set:
Commit: e365cf2b001af7ca0883d293b7c148bcaa8e1c61

[Gerrit Updater]

Minh Diep ([e-mail]) uploaded a new patch: https://review.whamcloud.com/36776
Subject: LU-12530 utils: narrow l_tunedisk udev rule
Project: fs/lustre-release
Branch: b2_12
Current Patch Set: 1
Commit: f5f3f9388aa9fa2c8eb7f2e83b3eb1912afea1fd

[Peter Jones]

Landed for 2.14

[Gerrit Updater]

Oleg Drokin ([e-mail]) merged in patch https://review.whamcloud.com/36599/
Subject: LU-12530 utils: narrow l_tunedisk udev rule
Project: fs/lustre-release
Branch: master
Current Patch Set:
Commit: 7b2cb54858daa60d560fd6374c4ecba552a10d27

[Olaf Faaland]

After this lands, please consider backporting to b2_12. Thanks.

[Gerrit Updater]

Olaf Faaland-LLNL ([e-mail]) uploaded a new patch: https://review.whamcloud.com/36599
Subject: LU-12530 utils: narrow l_tunedisk udev rule
Project: fs/lustre-release
Branch: master
Current Patch Set: 1
Commit: daa0f160640a6a3e5581e1f10ad33047a8a44ae6

[James A Simmons]

One day ext4 will be what is ldiskfs today. So Nathaniel approach is the best idea.

[Nathaniel Clark]

For ldiskfs type, I think, the closest you can get is checking the FS_LABEL, that it matches one of these:

MGS
*-MDT*
*-OST*

If it doesn't match one of those, then it definitely isn't ldiskfs.

[Olaf Faaland]

I don't see another udev property that would help distinguish ext4-formatted devices from ldiskfs-formatted devices, but if you know of one that would be even better.