Zpool surgery

[Daniel Hagerty]

Ulrich Spörlein <uqs at FreeBSD.org> writes:

> But are you then also supposed to be able send incremental snapshots to
> a third pool from the pool that you just cloned?

    I can't speak to your problems, but I did recently do what you seem
to be doing, without incident.  That is, I had a pool and an archive.  I
copied datasets from pool to a new pool', and pool' could send to the
archive as if it were the original pool.

    Two possible differences in what I do that leap to mind:

1. I only send select snapshots to archive; the synchronization
snapshots are not among them.
2. I use receive -F.

> How does the receiving pool known that it has the correct snapshot to
> store an incremental one anyway? Is there a toplevel checksum, like for
> git commits? How can I display and compare that?

    I don't know for sure, but I'd hazard a guess that:

$ zfs get -p guid pool/home at daily-2013-01-28
NAME                        PROPERTY  VALUE  SOURCE
pool/home at daily-2013-01-28  guid      259258190084829958  -

    plays a part.

    Good luck!