I have several servers powering syslog including it’s Raspberry Pi mirror, load balancer and email servers. All of my servers are hosted using Linode in their London data centre and have Linode’s back-up system doing both daily and weekly snapshots.
For the app and database servers I do server-side backups storing each website and it’s database in it’s own folder within /backup in case I require a quick back-up to fix something, rather than the server has died.
This is all well and good but I like having an off-site backup too and for that I use S3…
Amazon’s S3 is pretty cheap and very easy to use. Because only data is going in you don’t pay a transfer fee and the cost of storage is very affordable, you can see a pricing list here.