zpool import with missing device

Question

I had two geli-encrypted partitions on separate disk in a zpool as simple disks (no raid*). I didn't want redundancy for all files, only for some selected datasets (for which I set copies=2).

Now one disk died (controller doesn't respond anymore), and I'd like to get the files back that are on the remaining disk - but it looks like this is impossible.

# zpool import
  pool: data
    id: 9847503418894158179
 state: UNAVAIL
status: One or more devices are missing from the system.
action: The pool cannot be imported. Attach the missing
        devices and try again.
   see: http://www.sun.com/msg/ZFS-8000-6X
config:

        data          UNAVAIL  missing device
          ada0p3.eli  ONLINE

        Additional devices are known to be part of this pool, though their
        exact configuration cannot be determined.

# zpool import -o readonly=on -R /mnt -f data
cannot import 'data': one or more devices is currently unavailable

All operations that in some way try to repair a pool require it to be imported, and I can't get import working.

So, finally, the question: is it possible to get those files back without the second disk?

(running debian/kFreeBSD 9.0, ZFS pool version 28)

You created a zpool that requires both disks to function. It's time to restore from your backups. — Michael Hampton, Mar 05 '14 at 12:01

score 3 · Accepted Answer · edited Apr 13 '17 at 12:14

3

The ZFS feature set copies=2 was not designed to overcome disk failures (see the comments on the following Q&A):

ServerFault: How do you restore the correct number of copies after losing a drive

The issue here being that as your pool is made of single disks, ALL disks must be healthy for import.

This can only be done in your case by recovering (through backup) the failed disk into a new one.

edited Apr 13 '17 at 12:14

Community

1

answered Mar 05 '14 at 14:34

Ouki

1,427

2

Also, I don't think the second disk was unhealthy... just a controller issue. Assuming all disks are physically okay, getting them onto healthy hardware should allow the import. – ewwhite Mar 05 '14 at 14:41
Thanks for the clarification. While the disk was still spinning with power the controller didn't respond. As the other disk was the same model I tried switching the "controller", but it didn't help. – Stefan Mar 05 '14 at 14:57

zpool import with missing device

1 Answers1