How to Resize ZFS

If you’ve been experimenting with ZFS, as we have, you’ve been struck by some of its limitations. One of the most common complaints is that it’s not flexible in terms of sizing – you have to add a whole new “vdev” (analogous to a RAID set) in order to expand, rather than simply adding new disks one at a time.

But there is one other way to expand a zpool – by iteratively swapping out every disk in the pool with a larger one and letting ZFS heal the pool. This is the technique demonstrated by Harry D in a two-part blog post:

1. How to resize ZFS
2. How to resize ZFS – Part 2 (the real world)

You still can’t shrink a zpool. Let’s hope that comes along soon, along with more flexibility in general. Otherwise, ZFS will be much less interesting in the desktop/workstation/small server space!