On Jan 19, 2010, at 22:54 , Ian Collins wrote: > Allen Eastwood wrote: >> On Jan 19, 2010, at 18:48 , Richard Elling wrote: >> >> >>> Many people use send/recv or AVS for disaster recovery on the inexpensive >>> side. Obviously, enterprise backup systems also provide DR capabilities. >>> Since ZFS has snapshots that actually work, and you can use send/receive >>> or other backup solutions on snapshots, I assert the "problem" is low >>> priority. >>> >>> >> >> >> What I have issue with is the idea that no one uses/should use tape any >> more. There are places for tape and it still has value as a backup device. >> In many cases in the past, ufsdump, despite it's many issues, was able to >> restore working OS's, or individual files. Perfect, not by a long shot. >> But it did get the job done. > >> As was pointed out earlier, all I needed was a Solaris CD (or network boot) >> and I could restore. Entire OS gone, boot and ufsrestore. Critical files >> deleted, same thing…and I can restore just the file(s) I need. And while >> it's been a few years since I've read the man page on ufsdump, ufsrestore >> and fssnap, those tools have proven useful when dealing with a downed system. >> > For a full recovery, you can archive a send stream and receive it back. With > ZFS snapshots, the need for individual file recovery from tape is much > reduced. The backup server I manage for a large client has 60 days of snaps > and I can't remember when they had to go to tape to recover a file. > > -- > Ian. >
Let's see… For full recovery, I have to zfs send to something, preferably that understands tape (yes, I know I can send to tape directly, but how well does zfs send handle the end of the tape? auto-changers?). Then for individual file recovery, I have snaphots…which I also have to get on to tape…if I want to have them available on something other than the boot devices. Now…to recover the entire OS, perhaps not so bad…but that's one tool. And to recover the one file, say a messed up /etc/system, that's preventing my OS from booting? Have to get that snapshot where I can use it first…oh and restoring individual files and not the entire snapshot? At best, it's an unwieldy process. But does it offer the simplicity that ufsdump/ufsrestore (or dump/restore on how many Unix variants…) did? No way. I suppose it might be fair to say, strictly speaking, that backup/restore probably should be dealt with as a "ZFS" issue. It's kind of ironic that Microsoft offers a backup utility and Sun is basically dropping theirs. It might be better to frame the debate somewhere else, but zfs send/receive and snapshots are not the same as a built-in OS utility for backing up and restoring the OS and OS files. A simple, effective dump/restore that deals with all the supported file systems, can deal with tape or disk, and allows for complete OS restore or individual file restore, and can be run from a install CD/DVD. As much as I love ZFS and as many problems as it does solve, leaving this out was a mistake, IMO. _______________________________________________ zfs-discuss mailing list zfs-discuss@opensolaris.org http://mail.opensolaris.org/mailman/listinfo/zfs-discuss
