freebsd stable - Nov 2016 - Help! two machines ran out of swap and corrupted their zpools!

> zpool import -N -O readonly=on -f -R /mnt/somezpoool
>
> If that doesn't help try:
>
> zpool import -N -O readonly=on -f -R /mnt/somezpoool -Fn
I got someone to do this (am still having toruble finding time
as am supposed to be off sick) and it causes instant kernel panic
on trying to import the pool. Same as it does on boot.
> Drop us a line of your configuration and used ZFS features. Like dedup, 
> snapshots, external l2 logs and caches.
10.3-STABLE r303832 from start of August. One simple pool, two
drives mirrored, GPT formatted drives. No dedup, no snapshots,
no external logs or caches. We have lz4 comression enabled on the
filesystem, but apart from that its an utterly bog-standard setup.

Am an leaning towards faulty hardware now actually... seems most likely...

-pete.

At one point lz4 wasn't supported on boot, I seem to remember that may 
have been addressed but not 100% sure.

If it hasn't and your kernel is now compressed that may explain it?

Have you tried booting from a live cd and checking the status of the pool?

On 22/11/2016 08:43, Pete French wrote:
>> zpool import -N -O readonly=on -f -R /mnt/somezpoool
>>
>> If that doesn't help try:
>>
>> zpool import -N -O readonly=on -f -R /mnt/somezpoool -Fn
> I got someone to do this (am still having toruble finding time
> as am supposed to be off sick) and it causes instant kernel panic
> on trying to import the pool. Same as it does on boot.
>
>> Drop us a line of your configuration and used ZFS features. Like dedup,
>> snapshots, external l2 logs and caches.
> 10.3-STABLE r303832 from start of August. One simple pool, two
> drives mirrored, GPT formatted drives. No dedup, no snapshots,
> no external logs or caches. We have lz4 comression enabled on the
> filesystem, but apart from that its an utterly bog-standard setup.
>
> Am an leaning towards faulty hardware now actually... seems most likely...
>
> -pete.
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Pete French wrote:
>> zpool import -N -O readonly=on -f -R /mnt/somezpoool
>>
>> If that doesn't help try:
>>
>> zpool import -N -O readonly=on -f -R /mnt/somezpoool -Fn
>
> I got someone to do this (am still having toruble finding time
> as am supposed to be off sick) and it causes instant kernel panic
> on trying to import the pool. Same as it does on boot.
Instapanic, huh...

Ok, let's put documentation aside and focus on unsupported development 
features.

You'll need a list of available transactions:

zdb -ul <vdev>

This one when given a vdev lists all uberblocks with their respective 
transaction ids. You can take the highest one (it's not the last one) 
and try to mount pool with:

zpool import -N -O readonly=on -f -R /mnt/somezpool -F -T 
<transaction_id> <pool>

Then check available filesystems. If it breaks again - retry with older 
transaction id.


-- 
Sphinx of black quartz judge my vow.