[wellylug] Rotating backups

[David Antliff]

On Mon, Apr 30, 2012 at 07:12, Phil Donaldson <philtm at anyware.co.nz> wrote:
> I like the sound of the offsite diff backups.
> And I'm looking for a backup product - have tried custom scripts and they're too much work and hard to support.
> I guess I've avoided diff backups so far due to a fear of one piece of the diff failing and making my whole backup useless.
> Do tools like Bacula and duplicity prevent this?
>
> To answer Duane's question, for now I need to backup files and a database from my file server.

I've been using 'rsnapshot' with great success for about a year now.
It backs up my file server to a removable HDD every 4 hours, and keeps
daily & weekly  incremental revisions. It uses rsync-generated hard
links (much like Apple's Time Machine) to create complete backups of
every iteration, so there are no 'diffs' as such, but you can still
work out what has changed between any two revisions, and easily delete
any revision if you desire. The trade-off with hard links is that you
don't have multiple *physical* copies of a file on the backup volume
(but this is only one of three 'places' every file exists, so that's
fine), and modifying a file in any way creates an entire copy (which
can be inefficient in terms of storage for very large files, but I
have a huge backup volume so no problem there either).

Of course it's configurable but pretty easy to get going. It meets all
my needs and is reliable. It's also *very* easy to restore files from
because every incremental is a full snapshot, you can restore a file
simply with 'cp'.

http://rsnapshot.org/

I set up a WebMin task to unmount/remount the volume so I can quickly
spin-down and swap disks with my workstation or cellphone on the LAN.

-- David.