Jon, Thanks for the 101 course -- that was very helpful. I'm now wondering if amanda is what I really need. I have a 90 GB single-tape drive and (currently) about 15 GB of uncompressed files (from du -k) to be backed up. Incremental backups should be in the 10-50 MB range (uncompressed). And to top it off, it's (currently) a single client machine. So a single tape should last me a long time! I want a low-maintenance automated backup system that will just email me when I've filled a tape and need to stick in a new one. Perhaps amanda is way overkill for me right now. Can anyone suggest an alternative? Hopefully one that is exceedingly simple for a novice to operate?
Keith. > -----Original Message----- > From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] > On Behalf Of Jon LaBadie > Sent: Wednesday, December 21, 2005 2:37 PM > To: [email protected] > Subject: Re: Do Overs > > On Wed, Dec 21, 2005 at 11:58:05AM -0800, Keith Nicewarner wrote: > > I'm new to backups (much less Linux or AMANDA), so forgive me if I'm > > missing some basic concepts. > > > > > > .... I think I've resolved the last issue, but here's the > > annoying thing: It keeps wanting me to put in a new tape - > > even though the previous tape wasn't full or even used. > > Is this normal? > > > OK, basic concepts 101 on tape usage. > > Amanda only overwrites tapes, it never ever ever appends > to the end of a tape it used in an earlier session. So > don't even think about running amdump today, sending the > data to a tape and then adding tomorrows run to the same tape. > > Early in a dump run amanda will see if it has a valid tape > to use. When it does find one it writes some amanda metadata > to the start of the tape (aka the amanda tape header). As far > as amanda is concerned, any data that was on that tape before > this is gone, even if it doesn't write any backup data to the > tape. I.e the tape has been "overwritten", the data is gone. > Amanda can also free up the index files and logs for the earlier > dump on that tape. > > Amanda expect you to label and rotate the usage of a number > of tapes. The number of tapes is your choice, but a good > rule of thumb for the minimum suggested is 1 plus twice the > number needed for taping a dumpcycle. I have a dumpcycle of > 7 days, 6 runs per dumpcycle and I generally use only one tape > per run. So my minimum according to that formula is 1 + 2 * 6, > 13 tapes. Remember that is a recommended minimum, I actually > rotate 24 tapes. > > You inform amanda of how often it can reuse tapes with the > tapecycle parameter. If you set tapecycle to 5, then it can > not reuse the last used tape until 4 other tapes have been used. > Tapecycle does not have to match the actual number of tapes in > rotation. My tapecycle parameter is 18 though I rotate 24. > This lets me gracefully handle (i.e. no action on my part) > situations like the occasional dump that needs two tapes to > compete or the occasional failed tape. > > > Since I haven't really gotten a good backup, how can I > > start fresh? It won't let me reuse the test tapes. > > How can I wipe the tapes clean and make AMANDA think > > it's the first day of operation? > > > > To reuse a tape, use amrmtape then relabel it (probably -f option). > > I once ran a script to refresh a config directory to starting > state. But it was a long time ago, so no guarentees. I think > it removed the logs, reports, curinfo, and indexes. In my case > I keep these in separate directories under the config root so > it was easy. Optionally I also I recreated, from previously > saved copies, tapelist, amanda.conf, changer.conf, ??? > > -- > Jon H. LaBadie [EMAIL PROTECTED] > JG Computing > 4455 Province Line Road (609) 252-0159 > Princeton, NJ 08540-4322 (609) 683-7220 (fax)
