[oi-dev] zfs on illumos needs an update to support specific slice with -d

[Atiq Rahman]

Hi,
This comes up in my mind.

Has anyone else observed that illumos has difficulty detecting ZFS pools
when they reside on a partition rather than occupying the entire disk?

On Mon, Oct 20, 2025 at 10:07 PM Atiq Rahman <atiqcx at gmail.com> wrote:
>
> Hi Peter,
> Thank you for your input.
>
> > The unqualified import checks every slice/partition on every disk. So it's
> > already looking at that partition. If it's not finding the pool, then
> > that's the problem you need to look at.
>
> I have an SSD with two partitions:
> 1. An EFI System Partition (512MB)
> 2. A ZFS pool occupying the remainder of the disk
>
> Neither ZFS nor OpenZFS reports any errors on this pool. However, when I try
> to import the pool using `zpool import` or with the `-d /dev/sdX` option (as
> translated to illumos device naming), the pool is not detected.
>
> Interestingly, on OpenZFS, if I specify `-d /dev/sdX2`, the pool imports
> successfully. That aside, this is pretty new and I have checked there is no
> corruption or issue with the pool itself.
>
> Given this, what could be the underlying cause for illumos/OpenIndiana not
> being able to detect or import this pool without explicitly pointing to the
> partition?