[OpenIndiana-discuss] zpool import not possible after slot change

[lists at mcintyreweb.com]

On Thu, Apr 22, 2021, at 1:15 PM, Reginald Beardsley via openindiana-discuss wrote:
>  I ran into this a long time ago trying to set up a ZFS image on a USB 
> drive for a laptop. Ultimately I gave up as it had to be plugged into 
> the "correct" USB port and that seemed to change unpredictably.

I think this should be OK if you run "zpool export" before unplugging the USB disk.  I agree that this may be difficult/impossible for a boot image though since you can't export the rpool while the system is running ...

> On Thursday, April 22, 2021, 03:01:03 PM CDT, Stephan Althaus 
> <stephan.althaus at duedinghausen.eu> wrote:
> The issue is, that the zfs import routine should read the zfs labels on
> the disks instead on insist on some device path.
> And in these cases just see if some other disk (that is not part of a
> successfully imported 'online' pool) has the correct zfs label for the
> "missing" disk.

I agree that this seems to be a bug, which could be filed against illumos/zfs.  But it may be dangerous to change without a ZFS expert confirming there is not some other case that would break without the current logic.  For example there might be complications for systems with multipath IO.  In my case it was a lot easier to fix via disk plugging rather than learning how to edit the kernel.

FWIW, deleting /etc/zfs/zpool.cache did not fix this, so the problem appears just by reading the paths on disk.

Hugh.