zfs send -R [PSARC/2007/574 FastTrack timeout 10/10/2007]

[Bill Sommerfeld]

On Wed, 2007-10-03 at 10:24 -0700, Matthew Ahrens wrote:
> Note, to receive any of these new type of "zfs send" streams, the
> receiving system must be running a software version capable of sending
> them.  Ie, the stream version is incremented.  However, no on-disk
> changes are required, so these streams can be received into old-version
> pools.  There are no changes needed to the user interface for "zfs recv"
> to receive these streams.

Q1: with respect to this stream version change alone, can an old "zfs
send" stream still be received by new software?

Q2: with the changes proposed by this case, is a "zfs send" not using
the new features sent using the older stream version or the newer
version?

This is motivated by an operational question: I run a couple servers
which have large zfs pools and which track nevada closely.  Another
group, which has a server running an s10 update, wants to do backups for
disaster recovery to one of my servers.  zfs replication of a small
number of filesystems would be the way to do it but for the current lack
of commitment to the stream format.

The ability for a new pool to receive old-format streams would seem to
be sufficient for this sort of use -- restores would (hopefully!) be so
infrequent that we could just use rsync or equivalent to push file
contents across.

					- Bill