Hello Anton, Friday, April 20, 2007, 9:02:12 AM, you wrote:
>> Initially I wanted a way to do a dump to tape like ufsdump. I >> don't know if this makes sense anymore because the tape market is >> crashing slowly. ABR> It makes sense if you need to keep backups for more than a ABR> handful of years (think regulatory requirements or scientific ABR> data), or if cost is important. Storing tape is much cheaper than ABR> keeping disks running. (Storing disks isn't practical over long ABR> periods of time; not only does the signal on the media degrade, but so do some components.) >> People just don't backup 300MB per night anymore. We >> are looking at terabytes of data and I don't know how >> to backup a terabyte a night. ABR> If you're actually generating a terabyte per day of data, I'm impressed. :-) ABR> Tape seems a reasonable way to back that up, in any case. A ABR> T10000 stores 500 GB on each tape and runs at 120 MB/sec, so a ABR> terabyte would take roughly 2.5 hours to backup with a single ABR> tape drive. LTO-4 is in the same ballpark. Of course, that ABR> assumes your disk system can keep up. ABR> The SAM-QFS approach of continuous archiving makes a lot of ABR> sense here since it effectively lets backups run continuously. I ABR> don't know how much Sun can say about the work going on to add SAM to ZFS. >> Or a really big question that I guess I have to ask, do we even care anymore? ABR> If we're serious about disaster recovery, we do. ABR> In particular, remote replication is NOT a substitute for backups. I can't entirely agree - it really depends. If you do remote replication and also provide snapshoting it will work extremely well. And your "restore" would be MUCH more efficient than from tape. Then if your primary array is down you just switch to secondary - depending on environment it could be all you need. With tapes not only you will have to wait for restore you also need a working array so you have a place to restore. Of course if you need to take your backup outside then that's different. I'm really disappointed that our try at adding zfs async replication hasn't worked out. We'll have to settle with 'while [ 1 ]; do snapshot; zfs send -i | zfs recv ; sleep 10s; done' ... -- Best regards, Robert mailto:[EMAIL PROTECTED] http://milek.blogspot.com _______________________________________________ zfs-discuss mailing list zfs-discuss@opensolaris.org http://mail.opensolaris.org/mailman/listinfo/zfs-discuss
