Offsite Multi TB Backup Solution?

Charles Curley charlescurley at
Sun Apr 26 09:22:52 MDT 2009

Sorry about breaking the threading. Oh, the joys of breaking in a new
mail client.

On Sun, 26 Apr 2009 08:33:33 -0600
Kimball Larsen <kimball at> wrote:

> Begin forwarded message:
> > From: Kimball Larsen <kimball at>
> > Date: April 25, 2009 12:00:46 AM MDT
> > To: "Provo Linux Users Group Mailing List - 100% Unmoderated,
> > High Traffic" <plug at>
> > Subject: Re: Offsite Multi TB Backup Solution?
> >
> >
> > On Apr 24, 2009, at 5:51 PM, Charles Curley wrote:
> >
> >> On Fri, Apr 24, 2009 at 04:32:38PM -0600, Kimball Larsen wrote:
> >>> Good thoughts - but I'm now in the Boise area. :)
> >>>
> >>> I've
> >>> read that amanda can be set up to store a copy of the backups on
> >>> an AmazonS3 share.  Does anyone here have any experience doing so?
> >>
> >> I have no idea whether Amanda can do that, but what I have done
> >> could be useful.
> >>
> >> Back up to external drive A, using Amanda's virtual tape setup.
> >>
> >> Have two more expternal drives, B and C. Swap between them. One is
> >> installed and the other off site, with weekly rotation. Use a
> >> script based on rsync to keep the installed one up to date.
> >>
> >> The application here is: If you can rsync to Amazon, you're in. Or
> >> forget Amazon and just do what I do, rotate between two drives.
> >>
> >> (Why use an external drive for A? So you can move it to another
> >> machine if you need to.)
> >>
> >> How much data do you have to back up?
> >
> > This is an interesting idea.  I have quite a bit of data.  I'm
> > using backuppc at the moment, and it reports a current pool size of
> > just about 600 GB.  This represents roughly a month's worth of
> > backups (done ever 6 hours on most hosts, with full backups done
> > every 2 weeks, incrementals done in between) for 8 hosts, including
> > our production servers and main work computers for all employees.
> > I've heard that backuppc is more efficient at storing backups
> > because it uses hard links - will amanda consume significantly more
> > space to provide as many backups?

Well, it looks as though two terabyte external drives should do you.
You'll need to see if rsync handles hard links correctly. (Hard links,
unlike sym links, only work on the same partition, BTW.)

Amanda does not use linking to handle duplicate files, so its backups
would be considerably larger.

Besides, if backuppc works for you now and will work with the scheme I
described, why switch to another backup program.

Some other thoughts:

If you do a full backup every two weeks, then you only need four
weeks' data, not a full month's.

If you do a full backup every two weeks and (I assume) the full
backups are staggered, then you should probably swap the off site
drives every two weeks as well. The off site backups should include the
most recent full backup and every subsequent incremental.

> >
> > For example, if Amanda will take up 2TB to store the same amount
> > of backup data as backuppc does today, It's not so simple as
> > external drives, unless I want to drop a bunch of dough on desktop
> > RAID systems and just swap them out back and forth.

Right. But carrying around a bunch of RAIDed drives is a nuisance, and
people tend to avoid nuisances.

Look into portable NAS boxes as well, but they may be overkill.

> >
> > Now, we don't mind spending some money to get a good solution in  
> > place, but before we do we want to investigate as many options as  
> > possible and make sure we are choosing the most elegant and / or  
> > cleanest solution.

Good way to think about it.


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