ZFS pool cannot be imported after power loss

[spinoza813]

I have been running NAS4Free 9.1.0.1.847 for about 6 months now. I have 4 4TB drives encrypted in RAIDZ2. The NAS is on an UPS, however the power cable came unplugged while moving some other cabling around, causing a power loss. Unfortunately, this may have been while a windows system was writing a large file to the NAS (I'm not sure). Now, I can attach the encrypted drives, but I cannot import the on-disk zpool configuration. When I try to import the zpool in command line, it reports no such pool can be found. I have a backup of the drives' meta data, but it is about 1 month old and lots of data has been added to the pool since I downloaded the meta data.

Any recommended troubleshooting tips would be much appreciated. Thanks in advance.

[raulfg3]

please post zpool import {yourpoolname} and zpool import -f {yourpoolname}

and revise documentation:

http://docs.oracle.com/cd/E19253-01/819 ... index.html

https://pthree.org/2012/12/10/zfs-admin ... ng-zpools/

[spinoza813]

My steps are:
Turn on NAS
Login to web GUI and mount all 4 encrypted drives. Output in web GUI is:

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 Attached to /dev/ada4.
Done.

Next, I SSH in as root using putty and do the following:

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nas: ~ # zpool import pool16tb
cannot import 'pool16tb': no such pool available

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nas: ~ # zpool import pool16tb -f
cannot import 'pool16tb': no such pool available

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nas: ~ # zpool import -f pool16tb
cannot import 'pool16tb': no such pool available

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nas: ~ # zpool import -f
no pools available to import

I could try

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zpool import -Df

However, the pool was never destroyed, it just wasn't exported prior to power off, so I'm not sure if this is the right move.

I should have a snapshot, from when the pool was working, but I'm guessing that doesn't matter if I can't import.

My next step may be to boot from a Live FreeBSD CD. I've heard the full FreeBSD distro has more ZFS tools and may be able to roll back to previous working versions. This person had a different problem and was using FreeNAS, but similar symptoms: http://forums.freenas.org/threads/help- ... port.3193/

I'm looking at FreeBSD 9.2 since I think it uses ZFS V28 as does NAS4Free 9.1.0.1.847. Is that correct?

[substr]

yes, freebsd 9.2 should be fine.

snapshots are of no use if the pool won't import.

Try 9.2 and report back.

[spinoza813]

After booting from FreeBSD 9.2, my results are the same.

attach all four encrypted disks:

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root@:~ # geli attach /dev/ada1
enter passphrase:
GEOM_ELI: Device ada1.eli created.
GEOM_ELI: Encryption AES-XTS 128
GEOM_ELI:        Crypto: software

Try to mport pool:

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root@:~ # zpool import pool16tb 
cannot import 'pool16tb': no such pool available

root@:~ # zpool import pool16tb -f
cannot import 'pool16tb': no such pool available

root@:~ # zpool import
no pools available to import

root@:~ # zpool import -f
no pools available to import 

root@:~ # zpool import -fF
no pools available to import

Again the encrypted disks attach properly, but I cannot import the pool. Would restoring old metadata backups in the NAS4Free GUI help? What do the meta data files backup exactly? Again, I have added significant amounts of data to the pool after backing up the meta data.

I also thought about trying to use 2 of the 4 disks at a time in each possible combination. It is RAIDZ2, so 2 of 4 disks is sufficient for accessing data. The thought being that 1 (or 2) of the disks is confusing the ZFS import process. This doesn't make much sense to me, but I'm out of ideas.

[substr]

I assume the metadata is the GELI metadata. In that case, I don't think it would be helpful unless it turns out you have already mismatched the GELI metadata. (You would know you had done this; the power loss wouldn't do it.)

Doubt it will help, but try the -fF options with the pool name given. You can also try -fFX with the pool name given. Usually, those options are helpful when you get a pool error, rather than no pool found.

Removing one drive at a time and trying the import might be a good idea. I think it has worked for other people when it turns out one drive has somehow gotten bad top-level ZFS metadata. Perhaps someone else will have comments?

[raulfg3]

try to install FreeNAS and import your ZFS pool , have a good Geli support: http://doc.freenas.org/index.php/Volumes