On Sat, Jan 11, 2014 at 12:31:52PM -0800, Andrius D. Ilgunas wrote: > Hmm...Jon's question got me to a'thnkin' about something that I haven't yet > read about. > > So let's say the dump cycle is 30 days and I want to keep a copy of the > previous month's dump before the tape1 gets overwritten so that I can keep > a record of the state of the database from two months ago. > > If I understand the terminology, this would be an archive?
Andrius, You might want to read further about the way Amanda differs from most backup systems. Typically they act as you are describing, a full dump of everything once in a while and incrementals in-between. So you get a monster dump followed by a bunch of small dumps. Amanda tries to level out the size of the dumps. You define objects to be backed up, called DiskList Entries (DLEs) in Amanda, and how you want them backed up (they need not all be the same). Amanda then spreads the full back ups of the DLEs across the whole dump cycle. At the beginning of each dump run Amanda spends time determining how big a dump it expects from each DLE as several levels, at least two, level 0 full and level 1 incremental. Then it determines how best to achieve balanced dumping while still keeping to your defined parameters. For any specific DLE it may continue to do a level 1 incremental, switch it to a smaller level 2 incremental, or promote it to an early level 0 full dump. > > So a strategy might be: on the 30th day, do a full dump, and copy it to > 'somewhere safe', whether on S3, or a DVD. That seems like a pretty > straight-forward concept, but might this idea be improved upon somehow? A strong recommendation is to never have less than two full dumpcycles. I suspect most Amanda installations maintain well over 2 dumpcycles. If you are reusing your storage media, and you only have one level 0, should it be overwritten by mistake or something bad happen to it, you only have less useful incrementals. Jon -- Jon H. LaBadie [email protected] 11226 South Shore Rd. (703) 787-0688 (H) Reston, VA 20190 (609) 477-8330 (C)
