New backup solution needed

No, this isn't about how the Synology NAS is giving me grief. The new NAS is doing everything I've asked of it and it's doing a mighty fine job of it. No, this time I'm not complaining.My storage solution before was a mess of external drives in enclosures. This was somewhat convenient because by backup was a one-to-one mapping between the external drives and backup drives. So, if I had a 2TB drive in my closet, I'd have a pair (one on-site, one off-site) of exact duplicate drives.This has some positives and negatives.The biggest negative is that I don't have redundancy on the main storage side. A positive is that if I did have a drive failure then I could just take the most recent backup and slot it into the enclosure and I'd be up and running again. A back-handed positive is that I had to manage the storage space myself. With one 1.5TB and three 2TB drives I had to shuffle stuff to and fro to keep anything from filling up -- this, of course, ensured that my backups were never full either.What I did over the weekend is whip up the start of a python script to help me manage the space and the backup process itself.Basically, the underlying framework of the backup remains the same: rsync. The problem is how to split up the data onto the different backup disks -- and guarantee that nothing gets missed. A secondary goal is to help the partitioning process.I'm most of the way done with the script, and I'll post that up when it's ready to go. Stay tuned!