[LU-3488] zfs mdt backup/recovery via snapshot

• Type: Story
• Resolution: Not a Bug
• Priority: Minor
• Affects Version/s: Lustre 2.4.0
• Environment: RHEL6.2

Epic/Theme

zfs

• Assignee: WC Triage
• Reporter: Scott Nolin (Inactive)

Description

I am testing recovering a failed metadata server via zfs snapshot.

Everything seems to go as expected, but when trying to mount the filesystem, either via the /etc/init.d/lustre start script I get an error about the backing filesystem:

[root@lustre2-8-25 ~]# mount -vt lustre lustre-meta/meta /mnt/lustre/local/cove-MDT0000
arg[0] = /sbin/mount.lustre
arg[1] = -v
arg[2] = -o
arg[3] = rw
arg[4] = lustre-meta/meta
arg[5] = /mnt/lustre/local/cove-MDT0000
source = lustre-meta/meta (lustre-meta/meta), target = /mnt/lustre/local/cove-MDT0000
options = rw
checking for existing Lustre data: not found
mount.lustre: lustre-meta/meta has not been formatted with mkfs.lustre or the backend filesystem type is not supported by this tool

I can manually mount it directly (posix I guess) to the filesytem with 'zfs mount' - and things look about right.

Have tried pawing through the init scripts but haven't found anything.

This could perhaps be a documentation note, and I'm missing something easy, so that's why I'm filing this as a 'story'. I see there are some issues open for zfs lustre documentation. Just don't know what to do, information is scarce.

Or, if this isn't supported there's always 'dd'?

Scott