I have used hardware RAID in the past, and I absolutely do not recommend it to anyone. My advice is to stay away from it like the plague. One should also realize RAID is *NOT* a backup solution. RAID and a backup solution do two different things. Most systems these days are better served by at least RAID6, given the size of readily available disks in the two digit terabyte range. Resyncing can in some cases take days, during which time a second disk failure is not all too unlikely. I maintain 2 backup solutions. The first is rsync. Every morning at 04:00AM, my backup server pulls over any new or updated files from my main server. I also keep off-site backups using the excellent dar utility (similar to the venerable tar utility, but designed for random access targets.)