UPDATE: 20191229 - Added how to rotate out the oldest backups.
As frequent readers may or may not remember, I rebuilt my primary server last year, and in the process set up a fairly hefty RAID-5 array (24 terabytes) to store data. As one might reasonably expect, backing all of that stuff up is fairly difficult. I'd need to buy enough external hard drives to fit a copy of everything on there, plus extra space to store incremental backups for some length of time. Another problem is that both Leandra and the backup drives would be in the same place at the same time, so if anything happened at the house I'd not only not have access to Leandra anymore, but there's an excellent chance that the backups would be wrecked, leaving me doubly screwed.
Here are the requirements I had for making offsite backups:
- Backups of Leandra had to be offsite, i.e., not in the same state, ideally not on the same coast.
- Reasonably low cost. I ran the numbers on a couple of providers and paying a couple of hundred dollars a month to back up one server was just too expensive.
- Linux friendly.
- My data gets encrypted with a key only I know before it gets sent to the backup provider.
- A number of different backup applications had to support the provider, in case one was no longer supported.
- Easy to restore data from backup.
After a week or two of research and experimentation, as well as pinging various people to get their informed opinions, I decided to go with Backblaze as my offsite backup provider, and Duplicity as my backup software. Here's how I went about it, as well as a few gotchas I ran into along the way.