Immediately after I first installed Amanda, I tested recovering. I restored some files, and did a cmp -l between them and their counterparts on the disk.
It's a good thing I did too, because there were random byte differences that did NOT affect the checksums or byte counts (ls -l) of these files. In other words, had I NOT done a cmp -l, I would never have known that there was a problem. I would have gone on, honky-dory, thinking I was getting good backups. one should always test his backups. I personally test them using cmp, about once every couple weeks. Only takes a minute. Michael Martinez System Administrator (Contractor) Information Systems and Technology Management CSREES - United States Department of Agriculture (202) 720-6223 -----Original Message----- From: R. Bradley Tilley [mailto:[EMAIL PROTECTED]] Sent: Wednesday, January 16, 2002 2:35 PM To: Stephen Hillier Cc: [EMAIL PROTECTED] Subject: Re: Linux and Sun Solaris dump / restore FAILS with amanda Thanks for the tip, dump has it's problems, and I only use GNU-tar with amanda because of those problems. Anyway, why didn't you use amverify on the tapes? Wouldn't it have prevented this disaster? On Wednesday 16 January 2002 14:11, you wrote: > Hi all, > > I don't normally post like this to any list, but recent experience (and > the pain thereof) prompted me to try and help others avoid what happened > to me. > > I've been using amanda for over a year in a production setting. It's > worked fine for the once-in-a-while single or multiple file-recovery. > But recently I had to try and do a full restore from a tape and it > failed miserably. What's worse, after inspecting the archive of tapes > that I have, not one of the dump images was complete and valid. Going > back through the amanda log files and email'd reports, I never found > errors for the tapes that gave me problems, but nontheless, the data on > the tapes was useless. Every dump archive was incomplete. > > I encourage all amanda users to restrict themselves to using GNU-tar. > While it doesn't save i-node information, it's very rare that you need > this in a recovery scenario. All you really need is the file and meta > data to do a recovery. With this in mind, and me still hurting from a > disaster from which we could not recover, I changed our entire backup > system to use GNU-tar instead of native dump utilities. Since then I 've > done 3 complete restores and they were all successful. > > No one should have to lose data like that. I encourage all users to test > their backups regularly. ESPECIALLY if you use native Linux/Sun dump > utilties. > > I also found it interesting that even Linus Torvalds hates the dump > utility and is lobbying to have it removed from all Linux distributions. > > For those who are curious, I manually inspected the useless dump > archives on my tapes. I 'amrestore'd them to disk, and used an > interactive restore to test their integrity. What I found is, while the > data and listings index did exist on tape, the actual dump archive was > always incomplete as if the backup ran out of spool space before it > finished getting the dump archive from the server being backed up. > > Good Luck to all. > > Stephen. -- Brad Tilley PBK OUB Linux Systems Administrator Phone: 540.231.6277 Web: http://bursar.vt.edu Fax: 540.231.3238
