On Wed, Sep 16, 2009 at 09:34, Erik Trimble <erik.trim...@sun.com> wrote: > Carson Gaspar wrote: >> >> Erik Trimble wrote: >> > I haven't see this specific problem, but it occurs to me thus: >>> >>> For the reverse of the original problem, where (say) I back up a 'zfs >>> send' stream to tape, then later on, after upgrading my system, I want to >>> get that stream back. >>> >>> Does 'zfs receive' support reading a version X stream and dumping it into >>> a version X+N zfs filesystem? >>> >>> If not, frankly, that's a higher priority than the reverse. >> >> Your question confuses me greatly - am I missing something? "zfs recv" of >> a full stream will create a new filesystem of the appropriate version, which >> you may then "zfs upgrade" if you wish. And restoring incrementals to a >> different fs rev doesn't make sense. As long as support for older fs >> versions isn't removed from the kernel, this shouldn't ever be a problem. > > You are correct in that restoring a full stream creates the appropriate > versioned filesystem. That's not the problem. > > The /much/ more likely scenario is this: > > (1) Let's say I have a 2008.11 server. I back up the various ZFS > filesystems, with both incremental and full streams off to tape. > > (2) I now upgrade that machine to 2009.05, and upgrade all the zpool/zfs > filesystems to the later versions, which is what most people will do. > > (3) Now, I need to get back a snapshot from before step #2. I don't want a > full stream recovery, just a little bit of data. I now am in the situation > that I have a current (active) ZFS filesystem which has a later version than > the (incremental) stream I stored earlier. > > > This is what a typical recover instance is. If I can't recover an > incremental into an existing filesystem, it effectively means my backups are > lost and useless. (not quite true, but it creates a huge headache.) >
Congratulations! You now know why you should use a backup program instead of zfs send for your backups. (There are more reasons than this) zfs send streams are not designed for backups! (But a backup program that understand zfs send streams and uses that instead of re cursing the filesystem would be nice...) _______________________________________________ zfs-discuss mailing list zfs-discuss@opensolaris.org http://mail.opensolaris.org/mailman/listinfo/zfs-discuss
