RE Backup plan and big filesystems

owner-amanda-users AT amanda DOT org a écrit sur 18/08/2006 15:06:48 : > Sorry for the length of the email, but it's been a bit difficult to > explain everything... :-) > > > Hi there, > I'm wondering which is the best backup technique that I can implement > on a Linux-only servers production environment. > > I was wondering initially, also under suggestion of some colleagues, to > stick with a cron-scripted solution, since they had the impression that > Amanda would just over complicate everything. > > Anyway this would require initial engineering time, like writing cron > scripts that would manage dump and tar utilities together mtx to manage > all the stuff. At this point in time, I'd rather go with a ready-to-go > solution like Amanda, even if initially we still would need some time to > spend on the configuration. Also, this will give us the fancy of > detailed email reports, that are always a good thing.

Amanda is easy to set up. Most probably, easier than writing a cron script.
> ...
> > > Other than this, I'm trying to figure out which is the best backup plan. > I'd go with a weekly full backup for everything (servers local > filesystems & GFS volumes) and an incremental daily. We will use 2 > different tape sets, to export physically tape cartridges from the data > center every week for data safety.

Forget about weekly full. Amanda uses a completly different logic:
Says you have 5 servers to backup and want every server to be full backuped at least once a week. Amanda will probably do something like:

full backup of server 1 on monday/ other servers incremental
full backup of server 2 on tuesday/ other servers incremental
full backup of server 3 on wednesday/ other servers incremental
full backup of server 4 on thursday/ other servers incremental
full backup of server 5 on friday/ other servers incremental

You don't have to tell Amanda what server has to be backuped when. Amanda will do it for you... It will simply respect your requirement of "at least every server must receive a full backup once a week"
> > What I'm a bit confused about is how to manage the tape cycles during > the week, and how to handle backup of big size filesystems (in our case > GFS). Actually the filesystem is of around 1TB, but I'm guessing if it > would be better to split it in different mountpoints, each of 400GB. > This would probably give some benefits for the backup, since this is the > exact size of our cartridges. > > If I'm not wrong, this is what it should be done: > > Monday 00:00 full servers filesystem dump into 1 cartridge; full GFS tar > into multiple tapes OR 1 cartridge for every single 400GB GFS filesystem > > Tue-Sun 00:00 incremental dump of servers filesystem; incremental GFS > tar as above > > The questions are: > > - How many cartridges do I need?

Say you need 1 cartidge per day, with your backup scenario you will need at least 2(weeks)*5(days)*1(tape_per_run)+1 = 11 tapes
> - How cartridges should be rotated during the week?

Let Amanda do its job.
> - Is it possible to use a different set of tape for every week, e.g. two
> sets to be rotated weekly using a full backup every monday?

Don't think this way :-)
> > - Is it better to split the GFS filesystem into multiple 400GB volumes > to improve the ease of backup?

Probably