unable to boot a healthy zfs pool: all block copies unavailable

[Eugene M. Zheganin]

Hi.

On 06.11.2015 21:00, Alan Somers wrote:
> I notice that my 10.2-RELEASE VM prints the same message about "all
> block copies unavailable" and then continues to boot just fine.  So I
> wonder if that part is just red herring.  There is another possibility
> here: I have seen a bug where ZFS attempts to open the root pool's
> vdevs by path (eg ada0p3) but can't find them because disks have been
> replaced and no longer have their old devnames.  So vdev_geom searches
> through the list of geom providers looking for any provider with the
> correct ZFS GUID.  Normally it would find the right devname (eg
> ada1p3).  But sometimes, because the disks are partitioned, it will
> find the wrong partition first (eg ada1).  Since ZFS has labels at
> both the beginning and the end of each vdev, vdev_geom will see the
> label at the end of ada1 (really, it's the label at the end of ada1p3,
> but it shares the same LBA that a label at the end of ada1 would) and
> think that it opened ada1 successfully. vdev_geom_open will then
> return, and at some later date another part of ZFS will fail to read
> the MOS, and your boot will fail.
>
You are talking here about gptzfsboot being not smart enough, right ?
Since kernel itself is able to find that pool after being booted up from
alternative source. So it's a gptzfsboot issue, right ?

Eugene.