On Wed, 6 Jun 2001 at 8:44am, Karl Bellve wrote
> I am learning to use Amanda but it seems it has a problem, as everyone
> knows, backing up a filesystem larger than the tape.
>
> I have a 300GB Raid 5 system and a 35GB AIT tape drive. I would like
> to do a backup of the raid system with a full backup done atleast
> once/month.
>
> It seems the only option is to make a Amanda config file for each
> subdirectory inside the raid drive (limited to 10GB each). There are
> about 15 10GB directories, so I guess I need to make 15 config files?
You're almost there, but not quite. You only need one configuration.
That configuration will have a disklist entry for each "filesystem" you
want to back up. In your case, each disklist entry will be one of your
10GB directories.
Next, you need to choose your dumpcycle (how long between full backups of
each disklist entry), your runspercyle (how many times you'll run amdump
during the dumpcycle), your tapecycle (how many tapes you want amanda to
use), and, possibly, your runtapes (you can use chg-manual and be a tape
changer yourself ;).
So, if you want each directory fully backed up at least once a month,
running amdump only on weekdays and using one tape per amdump run, you
could do:
dumpcycle 4 weeks
runspercycle 20
runtapes 1
For that config, you'll need 20 tapes. I'd strongly recommend having a
few spares, for a tapecyle of 22 at least. If you want to be able to
recover data more than a month old, you'll need more tapes, of course. I
run with a dumpcycle of 2 weeks, runspercycle 10, but I've got 60 tapes.
To get yourself started, you'll need to add filesystems (directories) to
your disklist a few at a time. When you add a disklist entry, amanda will
have to do a full dump. So don't add more filesystems at once than you
have tape space.
> Will Amanda try and back up each 10GB directory each night? I can see
> that would be a problem since I don't have a tape changer. Also, my
> holder partition is only about 2GB.
Once you're up and running, amanda will spread the full backups throughout
the dumpcycle, doing incrementals of those filesystems not getting a full
that night. I *would* get a bigger holding partition, though. It should
be able to hold at least one filesystem image.
Finally, you'll need to use GNUTAR rather than dump, since dump can't
handle incrementals of directories.
Phew, that was a bit long.
--
Joshua Baker-LePain
Department of Biomedical Engineering
Duke University
