A simple tip for those that run any kind of database:
Be sure to replicate them in master-slave (or master-master). And base your backups on taking a slave down for backups.
Hot backups only work for very small databases - even those that are based on LVM snapshots, tarsnap, innodb hotbackups etc. With big databases, you will be most likely IO bound and a backup will take your site down.
If you have lots of load and lots of data then re-creating a slave will require lots of downtime. For Plurk.com we have had a 4 hour downtime due to re-creating a slave, so be sure to run a master-slave setup and have fresh slaves replicated at all times (we have learned this the hard way :)).
Hot backups only work for very small databases - even those that are based on LVM snapshots, tarsnap, innodb hotbackups etc. With big databases, you will be most likely IO bound and a backup will take your site down.
If you have lots of load and lots of data then re-creating a slave will require lots of downtime. For Plurk.com we have had a 4 hour downtime due to re-creating a slave, so be sure to run a master-slave setup and have fresh slaves replicated at all times (we have learned this the hard way :)).