On Fri, 2005-12-16 at 14:08, Matt Morgan wrote:
> I'm about to do my first Amanda install next week (or so I thought),
> so I pulled out my O'Reilly "Unix Backup and Recovery" book. It's from
> 1999, and refers to Amanda version 2.4.2, but it says "Amanda
> currently starts a new tape for each run and does not provide a
> mechanism to append a new run to the same tape as a previous run ...".
>
> So I thought, well, that's probably out of date and I went to check
> the docs at Amanda.org, which appear to have been written for v. 2.4.2
> as well and not updated (although the version I got through yum a
> couple days ago is 2.4.5).
>
> Can anyone tell me if this is still true? Also, it looks like Bacula
> works the other way--it keeps writing to a tape until it's full
> (although I can't tell yet if that's true over multiple jobs). Can
> anyone confirm that?
Yes, a 'run' is a daily set that may include many filesystems and
it can automatically schedule a mix of fulls and incrementals
among those filesystems to make them fit on the available
tape. But, it does want a new tape for every run.
> This is for a very small business, with employees who aren't in the
> office a lot. The idea was to change the tape weekly, but write
> differentials to it 6 nights a week, and a full backup once a week (or
> something like that). The tapes are easily big enough to hold that
> much, and changing them more often would be very expensive.
> Maybe I should just write a script and use tar.
You can give amanda a large amount of holding disk space where
it will spool the dumps before streaming to tape. It checks the
tape label and if the tape it wants is not available, it leaves
the disk copy until you do an 'amflush'. If you aren't going to
take the tapes offsite, you might as well let them sit on the
holding disk until someone feels like putting in a new tape
and flushing a week or so.
However, you normally don't use new tapes - you decide how
long a rotation you need, label that many tapes, and recycle
them. 10 tapes would probably be good for a rolling set
changed every weekday, and you can do a separate tar dump to
different tapes if you want an occasional long-term archive.
Actually, you'd probably make that 2 tape 'sets' of 5 in
the amanda config, and then amanda would make sure that
you get at least one full backup of every filesystem within
5 runs along with at least an incremental of each in every
run.
--
Les Mikesell
lesmikesell@xxxxxxxxx
