[OmniOS-discuss] snapshots on an exported pool

[Jim Klimov]

On 2013-11-06 19:07, Johan Kragsterman wrote:
> Hi!
>
>   I've been thinking of what happens to a snapshot that have been sent to a zfs pool that later have been exported, and the original filesystem, on another pool, still changes.
>
> What happens with the snapshot(and the relation between the snap and the original) when the pool is re-imported?

When you send a snapshot from your original pool, you have (logically)
the same data named as the same snapshot in the other pool. If both
snapshots continue to exist, you can send increments (from this snap
to a next one defined in the future) to update a remote target. This
requires that only one of the "live" datasets changes: changes on the
target are discarded (rolled back) and the new increment is added on.
However if you remove the original snapshot, you can't send increments
anymore with ZFS means - you would have to replicate starting with an
earlier common snapshot, or even with a full-sync from scratch. Also
you can sync in such case with rsync - but would no longer be able to
use zfs send for incremental sync...

//Jim