I'm busy buying hardware & getting educated to build a Tivo hd server (x2, 1 primary, 1 backup). I now get why RAID is good in addition to essential backup. But I really, really hate the limitation in standard RAID of same size drives in the array (or effectively same size as it will only make use of the size of the smallest drive in mixed drive array). One of the reasons I really hate this limitation is the long term expense of effectively making use of larger size drives only after either a long period of migration or a single costly replacement all at once. So I'm looking at some sort of standard RAID alternative and SnapRAID is bubbling to the top. http://snapraid.sourceforge.net/compare.html Looking okay to me because it's free, can mix drive sizes, uses a snapshot model, can recover data in non-failed disks, doesn't make my server into just a NAS like unRAID, etc. But I can be swayed on any of these reasons; I'm just feeling my way around and these are inchoate impressions. Any thoughts?