Oh no, what have I done...

[Paul Kraus]

> On Aug 12, 2017, at 9:22 PM, Chris Ross <cross+freebsd at distal.com> wrote:
> 
> 
>> On Aug 12, 2017, at 20:03 , Peter Jeremy <peter at rulingia.com> wrote:
>> 
>> On 2017-Aug-12 19:36:31 -0400, Chris Ross <cross+freebsd at distal.com> wrote:
>>> But, I fear I may’ve shot myself.  Is there any way to recover my raid1z vdev from this situation, and get a working zfs pool back?
>> 
>> There's no way to detach the vdev /dev/da2p1 - you need to backup and
>> re-create the pool.  You need to re-attach /dev/da2p1 so the pool can
>> be imported, then do a backup, destroy the pool and re-create it.
> 
>  Can I attach a different similar drive as da2p1?

Nope.

>  Or, does it have to have the same bits that were put on it when it was in the pool previously?  If the latter, I don’t have those bits any more.

The same disk. ZFS is looking for the labels it writes (4x for redundancy; 2 at the beginning of the disk and 2 at the end; it only _needs_ to find one of them) to identify the drive to include it in the zpool. If that disk no longer contains the ZFS labels then you are probably out of luck.

You _may_, and this is a very, very long shot, be able to force an import to a TXG (transaction group) _before_ you added the lone drive vdev.

> I’ll try putting a disk with the same layout in, and see how that goes.  That was a thought I’d had.

Won’t work, without the ZFS labels it will not be seen as the missing drive.