On Wednesday 25 June 2003 07:30, Roberto Samarone Araujo (RSA) wrote: >Hi, > > It it possible to use amanda to do diferential backups ? Are > there any specific configuration ? > Amanda will do differentials AFTER amanda has done a full. This is so that there is a baseline reference date established for that disklist entry.
But I think you mis-understand how amanda works. Unlike the other solutions, amanda tries to use about the same amount of tape every night. And amanda will juggle the schedule about, moving the dates of things up by sometimes as much as 5 days in trying to achieve that, and given enough time in dumpcycles, will do pretty well at this balanceing act. To recap: dumpcycle: The number of days (or weeks) that amanda has to do a full backup of each disklist entry in. A lot of folks run 7 days or 1 week. runspercycle: In case you are doing a monday to friday only run schedule, this tells amanda how many times amanda will be run in the above 'dumpcycle' number of days. Businesses often set this to 5 since theres not much going on over the weekends. runtapes: If you have a tape changer, this sets the number of tapes amanda will be allowed to use per run. tapecycle: The number of tapes in the rotating pool. Amanda will use every tape in the pool until it has used them all, and will then start to recycle them on an oldest first basis. This should be not less than 2x runspercycle*runtapes plus 2 or 3 for comfort in knowing that you have in fact at least 2 generations of full, level 0 backups on everything in the disklist. You wouldn't want to ever get in the situation where you were over-writing your only full backup of something, and have a power failure while doing that entry's lavel 0 again. Here at home, I'm useing 7, 7, 1, 28 settings. DDS2 tapes are cheap, and I actually have about twice that many in stock. Amanda has had enough time to arrive at a fairly consistent tape useage of above 90% fill each night. -- Cheers, Gene AMD [EMAIL PROTECTED] 320M [EMAIL PROTECTED] 512M 99.26% setiathome rank, not too shabby for a WV hillbilly Yahoo.com attornies please note, additions to this message by Gene Heskett are: Copyright 2003 by Maurice Eugene Heskett, all rights reserved.
