I have a RAID5 over a set of 3 internal SATA drives, then an external enclosure with 5 drives (RAID5) for backup connected to the same machine via eSATA, where

I have a RAID5 over a set of 3 internal SATA drives, then an external enclosure with 5 drives (RAID5) for backup connected to the same machine via eSATA, where an rsync job kicks off every night to sync between primary/backup volumes. No off-site backup, though, which I know is a single point of failure which I hope to remedy at some point.