On Tuesday 26 November 2002 23:41, Nitesh Kumar A. wrote: >Hai Joshua: > >Since level 1 backups everything since the last backup, that is > level 0, we will get replication of files (redundancy) > irrespective of whether the files are modified or not in the > subsequent backups on the rest of the days. In the sense on > saturday, we will get files, a, b, c, d and e too. > >So tuesday: a, b >wed: a, b, c >thu: a, b, c, d and so on. (irrespective of whether the files are >modified or not. this will result in redundancy). > >is there some mechanism to minimize it? y waste the tape.. . > >true, i will go through the website too. it might be very useful > indeed. > >> Amanda does not append to tapes -- you'll need to change tapes >> each day. > >so when will the tape drive1 get a chance to be overwritten? do we > need to relabel it again?
No. It will become re-useable when its name reaches the end of the list whose length is determined by how many tapes you have amlabeled, and the number of runs represented by the value of the amanda.conf 'tapecycle' have been used prior to its name coming up again. If you have tapecycle set for 20, then 19 other tapes must have been used before this one can be over-written. I'm not positive, but I think it will amlabel a blank tape IF that label isn't previously used, until such time as it has labeled $tapecycle tapes. But I've never done that, labeling mine ahead of time instead, so I can't lay my hand on the good book and swear to it. >thanQ and regards, >nitesh > > > > >On Tue, 26 Nov 2002 at 7:30pm, Nitesh Kumar A. wrote > >> I am really excited to know more about AMANDA now. >> >> What I understand is that, first amanda will take a level 0 >> backup (full backup) and then for the following days, it will >> take level 1. > >Usually. If the level 1s get too big, it may "bump" them to 2s or > higher. > >> If suppose, amanda takes level 0 on sunday and then level 1, >> with > >respect > >> to 0 on mon/tue/wed/thu/fri/sat. >> >> Now I have files named a, b, c, d, e, etc on my filesystem. I >> have the full backup on sunday. >> >> File "a" is modified on monday, so the level 1 backup on monday >> will > >just > >> have file "a". >> >> File "b" is modified on tuesday, so the backup on tuesday will >> have just file "b" but not file "a" due to just level 1 backup. > >That's incorrect. A level 1 backs up everything changed since the > last level 0. So Tuesday night's backup will have "a" and "b". > >> At some point of time, if I want to backup all the files, then I >> have to contact all the tape drives. Is this the case? Or will >> amanda tell me on which tape drives are these files located? How >> do I search for a particular file in the backup? > >The program "amrecover" offers a ftp-like interface to the > backups. You tell it what files you want (and from which data), > and it'll tell you what tapes you need. > >> So if just file "a" is written into the tape drive1, how can we >> use the rest of the space on the tapedrive1? > >Amanda does not append to tapes -- you'll need to change tapes > each day. > >For more, please go read the amanda chater from "Unix Backup & > Recovery", available at > <http://www.backupcentral.com/amanda.html> as well as the docs in > the amanda tarball. They'll explain a lot of these basic > concepts. -- Cheers, Gene AMD K6-III@500mhz 320M Athlon1600XP@1400mhz 512M 99.19% setiathome rank, not too shabby for a WV hillbilly
