My thinking was that expanding your underlying md RAID would be the same as replacing the initial disk ZFS sees with a bigger one, thus enabling easier expansion at the md level and presenting a &quot;bigger disk&quot; to the zfs vdev.<p>I haven&#x27;t seen it done, it&#x27;s just a theory, hence why I asked. I&#x27;m just not sure if zfs needs to see actual disks, or if it can work on top of any block device, like an md RAID.