Basic RAID concerns and Linux OS 720

RAID is for getting your data back online *quickly*. If reliability is more important than speed, you should consider more traditional backups (like DATs, or just burning DVDs more frequently ...).

As others have said, the Linux Documentation Project is your friend. Beware out-of-date HOWTOs though. There is an important distinction between software RAID (md) and the Logical Volume Manager (lvm2), and you should read up on both before deciding exactly what to build on your disks. (Even more confusingly, you can have LVM2 volumes on md drives ...)

I think you're using "OS" to mean "Linux distribution" - if so then no it shouldn't matter. They should all have the latest versions of md and lvm2 available. IMHO your choice of distro is all about which package management system you prefer.

This is all about the physical configuration of your server, not about your OS. If you have front-facing hot-swap bays and spare drives handy, it can be done in seconds.

I confess that I've only ever had two HDs die on me, and neither was in a RAID array at the time, so I can't give you any views about the recovery experience. I would hope that rebuilding the array would be automatic.

CC