Ubuntu and ZFS, loses pool on reboot

Question

I'm using a fresh install of Ubuntu 12.04 LTS, with the ZFS PPA.

I'm finding when I create a pool it will mount and function fine, but after a reboot it shows as UNAVAIL and I can't find a way to get it back.

Here is a log of a quick test to demonstrate:

root@nas1:~# zpool status
no pools available
root@nas1:~# zpool create data /dev/disk/by-id/scsi-360019b90b24d9300174d28912b1c485d /dev/disk/by-id/scsi-360019b90b24d9300174d28a610419bec
root@nas1:~# zpool status
  pool: data
 state: ONLINE
 scan: none requested
config:

        NAME                                      STATE     READ WRITE CKSUM
        data                                      ONLINE       0     0     0
          scsi-360019b90b24d9300174d28912b1c485d  ONLINE       0     0     0
          scsi-360019b90b24d9300174d28a610419bec  ONLINE       0     0     0

errors: No known data errors
root@nas1:~# shutdown -r now

Broadcast message from root@nas1
        (/dev/pts/0) at 10:41 ...

The system is going down for reboot NOW!
root@nas1:~#
login as: root
Server refused our key
root@nas1's password:
Welcome to Ubuntu 12.04 LTS (GNU/Linux 3.2.0-24-generic x86_64)

 * Documentation:  https://help.ubuntu.com/

  System information as of Wed May 23 10:42:09 BST 2012

  System load:  0.48              Users logged in:     0
  Usage of /:   6.0% of 55.66GB   IP address for eth0: 10.24.0.5
  Memory usage: 1%                IP address for eth1: 192.168.30.51
  Swap usage:   0%                IP address for eth2: 192.168.99.41
  Processes:    142

  Graph this data and manage this system at https://landscape.canonical.com/

Last login: Wed May 23 10:40:06 2012 from 192.168.100.35
root@nas1:~# zpool status
  pool: data
 state: UNAVAIL
status: One or more devices could not be used because the label is missing
        or invalid.  There are insufficient replicas for the pool to continue
        functioning.
action: Destroy and re-create the pool from
        a backup source.
   see: http://zfsonlinux.org/msg/ZFS-8000-5E
 scan: none requested
config:

        NAME                                      STATE     READ WRITE CKSUM
        data                                      UNAVAIL      0     0     0  insufficient replicas
          scsi-360019b90b24d9300174d28912b1c485d  UNAVAIL      0     0     0
          scsi-360019b90b24d9300174d28a610419bec  UNAVAIL      0     0     0
root@nas1:~#

EDIT

As requested, output of ls -l /dev/disk/by-id/scsi-*:

root@nas1:~# ls -l /dev/disk/by-id/scsi-*
lrwxrwxrwx 1 root root 9 May 23 12:03 /dev/disk/by-id/scsi-360019b90b24d9300174d28912b1c485d -> ../../sdb
lrwxrwxrwx 1 root root 9 May 23 12:03 /dev/disk/by-id/scsi-360019b90b24d9300174d28a610419bec -> ../../sdc
lrwxrwxrwx 1 root root 9 May 23 12:03 /dev/disk/by-id/scsi-360019b90b24d9300174d28b1031dd786 -> ../../sdd
lrwxrwxrwx 1 root root 9 May 23 12:03 /dev/disk/by-id/scsi-360019b90b24d9300174d28baf7edd45e -> ../../sde
lrwxrwxrwx 1 root root 9 May 23 12:03 /dev/disk/by-id/scsi-360019b90b24d9300174d28c5ea9c6198 -> ../../sdf
lrwxrwxrwx 1 root root 9 May 23 12:03 /dev/disk/by-id/scsi-360019b90b24d9300174d28d1db783151 -> ../../sdg
lrwxrwxrwx 1 root root 9 May 23 12:03 /dev/disk/by-id/scsi-360019b90b24d9300174d28e6c0af4c8e -> ../../sdh
lrwxrwxrwx 1 root root 9 May 23 12:03 /dev/disk/by-id/scsi-360019b90b24d9300174d28eeb7d87669 -> ../../sdi
lrwxrwxrwx 1 root root 9 May 23 12:03 /dev/disk/by-id/scsi-360019b90b24d9300174d28f6ad29d90a -> ../../sdj
lrwxrwxrwx 1 root root 9 May 23 12:03 /dev/disk/by-id/scsi-360019b90b24d9300174d28fca5534028 -> ../../sdk

EDIT

I've just done some further testing. Rather than using id I tried just using sdb, sdc, etc:

zpool create data sdb sdc sdd sde

Same result. It created the pool but after a reboot it was "UNAVAIL".

EDIT

As requested, output of zdb -l /dev/sdb:

~# zdb -l /dev/sdb
--------------------------------------------
LABEL 0
--------------------------------------------
failed to unpack label 0
--------------------------------------------
LABEL 1
--------------------------------------------
failed to unpack label 1
--------------------------------------------
LABEL 2
--------------------------------------------
failed to unpack label 2
--------------------------------------------
LABEL 3
--------------------------------------------
failed to unpack label 3

I did that test after creating a new pool and had the same result.

EDIT

I just tried a completely fresh install of Ubuntu 11.04 (to rule out a bug in 12.04).

1. Added the PPA repository
2. Did a dist-upgrade, then installed ubuntu-zfs
3. Ran 'zpool create data sdb sdc'
4. Checked with zpool status and the pool showed there
5. Rebooted the server
6. Checked again, still there.

So it's a problem with my 12.04 instance. Tempted to just reinstall...

Answer 1

It turned out to be a faulty RAID controller that was handling the disks. Swapped out the controller, everything works fine now!

Answer 2

Do not be afraid, simply:

cd /path_to_your_disks
zpool import -d . <name_of_your_pool>

In my case it was located /disks. In your case perhaps it is located on /dev/disk/by-id.