On Fri, Jul 07, 2006 at 08:20:50AM -0400, Dennis Clarke wrote: > As near as I can tell the ZFS filesystem has no way to backup easily to a > tape in the same way that ufsdump has served for years and years. > > ... > > Of course it took a number of hours for that I/O error to appear because the > tape hit its capacity. There were no reports of 10% or 20% and no prompt > for "end of media" and "please insert a blank tape and hit enter when ready" > sort of thing. > > This ZFS filesystem is now in production. I think that someone had better > step up to the plate and suggest the method by which people are supposed to > do a backup. > > ... > > Really, I'm not happy here. > > I am more than able to read the ZFS Administration Guide and read the man > pages but I just don't see a manner to backup my ZFS filesystem to tape.
I am sorry to hear that you're not happy. However, please keep in mind that as part of any software product a series of tradeoffs have to be made. If we had included a backup program that knew how to deal with various flavors of tapes (as opposed to generating a byte stream as we do today), then there is something else we would have had to forgo. I'm sure that no matter what feature we left off, there is someone else on this list that would be equally angry that we left that feature off. And delaying N months to do both was just not an option. That said, we actually did talk to a lot of customers during the development of ZFS. The overwhelming majority of them had a backup scheme that did not involve ufsdump. I know there are folks that live and die by ufsdump, but most customers have other solutions, which generate backups just fine. Given a byte stream (which we give you today with "zfs send"), it should be relatively straightforward to write a program that will send a byte stream to tape, prompting for media changes as necessary (see mtio(7I) for the details of handling tapes). I think you'd just have to watch the return code of write(2) to detect logical EOT, use ioctl(MTIOCSTATE) to eject the tape and detect insertion, then resuming the writing. The read(2) would be quite similar. I don't have a tape drive myself, otherwise I'd consider just writing it. As for progress a progress indicator, that is an open bug (I can't seem to find the bugid right now, though). If there is something else we can do to help you out, let us know. --Bill _______________________________________________ zfs-discuss mailing list zfs-discuss@opensolaris.org http://mail.opensolaris.org/mailman/listinfo/zfs-discuss
