Problems replacing failing drive in ZFS pool

Garrett Moore garrettmoore at
Mon Jul 19 16:32:40 UTC 2010

The data on the disks is not irreplaceable so if I lose the array it isn't
the end of the world but I would prefer not to lose it as it would be a pain
to get all of the data again.

Freddie's explanation is reasonable, but any ideas why it didn't happen when
I replaced my first dead drive (da5)? That replacement was completely

The system is in a Supermicro case with a hotswap backplane:
The backplane ports are connected to a Supermicro AOC-USASLP-L8I LSI 1068E
8-PORT RAID 0/1/10 Uio SATA/SAS Controller.

By the way, Freddie, in your instructions in the 'reboot' step I assume that
is when I will be switching the physical drives, correct?

On Mon, Jul 19, 2010 at 12:18 PM, Adam Vande More <amvandemore at>wrote:

> On Mon, Jul 19, 2010 at 10:56 AM, Garrett Moore <garrettmoore at>wrote:
>> So you think it's because when I switch from the old disk to the new disk,
>> ZFS doesn't realize the disk has changed, and thinks the data is just
>> corrupt now? Even if that happens, shouldn't the pool still be available,
>> since it's RAIDZ1 and only one disk has gone away?
>> I don't have / on ZFS; I'm only using it as a 'data' partition, so I
>> should
>> be able to try your suggestion. My only concern: is there any risk of
>> trashing my pool if I try your instructions? Everything I've done so far,
>> even when told "insufficient replicas / corrupt data", has not cost me any
>> data as long as I switch back to the original (dying) drive. If I mix in
>> export/import statements which might 'touch' the pool, is there a chance
>> it
>> will choke and trash my data?
> I'm not sure what's going on in your case, but I have cron'd a zpool scrub
> for my pool on weekly basis to avoid this.  I run a / zfs mirror and one day
> I could no longer boot and saw the dread 'insufficient replicas'.  I
> eventually got it when disk started to work again briefly then did a
> snapshot/send offsite, redid system with new install & disk then restored
> data.  The export/import shouldn't hurt, I used that when booting off an
> MFSBSD cd and imported the zpool to send from there.  Perhaps you might want
> to consider RAIDZ2 with all those disks.
> --
> Adam Vande More

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