What is the best way to redundantly back up to external hdd so that one of the hdds can be unplugged daily to be taken off site?

Question

The problem I've got is that I have a Ubuntu 13.10 instance, running ownCloud, and I want to keep redundant backups of the data directory from ownCloud on two external drives (1tb, USB3).

The plan is that each day one or both of these external drives can be unplugged and taken away from the office so that, if something should happen to the office, we've still got a backup of the ownCloud data.

This is how I have things currently set up:

ownCloud data directory located in /var/www/owncloud/data, this is actually a symlink to /media/PRIMARY/data (the first USB hdd), so this one can't be removed at the moment without breaking ownCloud.

/media/PRIMARY/ is backed up to /media/SECONDARY using Déjà Dup (as bundled with Ubuntu as "Backup").

This setup isn't working for me, and I'm sure it's over-complicated.

I've not been very successful in looking for a better solution, so that brings me here. Are there any de facto ways to achieve what I'm trying to do?

Answer 1

I do this, with removeable drives that I rotate and carry off-site weekly. Each week I first make an LVM snapshot of the volume I want to back up:

lvcreate --size 10G --name snap --snapshot /path/to/file/system/device

Then I mount /dev/mapper/snap, and rsync it to an encrypted volume on my removeable drive. When it's done I unmount everything, delete the snapshot, and carry the removeable drive off-site.