Home Linux terrabyte backup system

This is something I've wanted to build for some time. I hadn't actually thought about a terrabyte of storage, but... linux journal has the article on making your own home network backup storage solution using an old pc, linux and relatively cheap discs. The concept of any backup system is redundancy so that a single failure doesn't take out your data.

I originally saw a post on this at osdir thought I'd never find the link....

Anyway, I've several times though for the price of another hard drive (or two) an old system would make a perfect "sit quietly and let me copy data from EVERY other machine" storage/backup solution. Mirroring to an offsite solution is also covered which gives great peace of mind for data redundancy.