Re: zfs panic VERIFY3U

On Tue, Jul 22, 2025 at 11:46:11AM -0600, Alan Somers wrote:
>
>From the panic, it looks like your vdev is smaller than what is recorded in
>the label.  I can think of a few reasons why that might be:
>* It's a VM, and you shrunk the size of the VM's disk.  ZFS can't tolerate
>that.

no, this is bare metal

>* You shrunk the size of the disk using some exotic SCSI commands.

no :)

>* The disk is broken in such a way that it reports mediasize 0.  I've seen
>that happen.  You can check with "geom disk list".

Might be, I can't tell just yet.

>* ZFS found an old label.  Perhaps it dates from before you expanded a
>vdev.  You might've pulled out a disk, then expanded the other disks in
>that RAID or mirror, then reinserted the old disk.  These problems are
>annoying, but solvable.  This is also one case where you might get
>different results if you import during boot vs after boot.

Possibly/probably the case

>Is this still a problem for you, or is it all solved?

The problem has changed in that there is no more zfs panic, 
but the disk (it was /dev/da7) has "disappeared" from /dev. 
It *is*, however, accessible from 'cciss,7 /dev/ciss0' via smartctl. 
I can't check geom because it's not seen in /dev at the moment.

The disk (da7) is SAT. The others are SATA. This has worked before,
the card is ciss0: <HP Smart Array P440> in HBA mode.
It can use SAT or SATA. Not sure if SAT *and* SATA might cause 
undocumented behaviour though.

The problem of the disk becoming unavailable in the pool has happened
before, in similar circumstances (power outage), but zfs never panicked.
That part is new.

Right now, zfs (deliberately) doesn't autoload. I'm going to try
make the system see da7 and if that works, then look at geom, clear that,
then load zfs.ko and zpool import -a. The last time that was done
(sans clearing geom), da7 resilvered and joined the pool.
All the other disks, apart from da0 (which isn't part of the pool)
show no geom (I understand that to be normal with raw disks)

thank you for your help & ideas,
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