Re: Tape/DVD Backup Suggestions?

> I advise against hard disk based backups:

Don't write off disk backups yet. I would have (and did) a year ago,
but in the last six months things have gotten a lot cheaper.

> It's not cheap, sure, a tape drive is expensive, but the tapes are quite
> cheap.
>
> The cheapness of the tapes allows you to use several for different
> backup strategies (weekly and daily incremental and monthly full backup, for
> example) and to keep older data on saved tapes.

Tape isn't as much cheaper as it used to be. IDE disks are going for
$132 for 120GB. You can do RAID 5 with 8 drives for around $1.25 a
gig. You can get tapes (DDS3) for about $.50 a gig (don't pay attention
to the max compressed size) but that doesn't factor in a lot of other
costs. Drives aren't cheap and neither are the people who'll be
changing your drives. You also won't pack that tape as well as you will
disks. When you cycle out your weekly set you'll be throwing away
unused capacity. Disks stay around until you use every last bit.

> It's easier. There are programs like Arkeia (free for one linux server and
> two clients (win32/linux)), that makes tape and backup management a few
> clicks (but a read of documentation is still needed). As a side note,
> Arkeia supports direct dumping and backup from serveral rdbms, postgresql
> included.

Not really. Just use pg_dump to dump to disk and write yourself a
wrapper to figure out a filename based on the date.

> It's more reliable. If the backup disk fails, all backup is lost and its
> substitution an hassle. If a tape breaks you still have the other tapes
> for last week/day/etc.. Still, a tape drive can fail or a tape can screw
> the drive, but I haven't heard of anyone to whom that has happened. In
> hardware world, quality normally comes with an higher price.

You won't lose data from disk if you use RAID.

I know it's hard to believe, but we're actually saving money dumping to
disk. We needed a new system and the decision of tape vs disk was made
based on cost alone.

Another benefit of disk is that all your backups are online. That comes
in really handy for postgres because you can do incs very easily with
diff. If you're looking to save money on postgres backups a good place
to start is not saving an epoch each day.

--Nate

--Nate