[K12OSN] why RAID?

[Dennis Daniels]

Does anyone mind if this little discussion gets wikified? Reading along 
here I learned a great deal. It should be captured and worked into a 
location that we can all use. Any opposition? I'll take silence as 
agreement ;^)

Dennis

Michael Wescott wrote:
>>why is it so important to get RAID set up?  Why not just
>>have a cron job that makes a copy of /home or any other
>>important directories?
> 
> 
> RAID levels 1 and 5 provide a sufficient redundancy that you
> can lose a disk without losing data. There are, of course,
> other tradeoffs; the redundancy comes at the price of additional
> disks and a performance impact on writes. There is also a gain in
> read performance.
> 
> But disk failures aren't the only way to lose data. A RAID
> decreases the probability that a hardware failure will cause
> data loss, but it has no impact on users or administrators
> deleting or overwriting a file. So having a RAID setup does
> not eliminate the need for doing periodic backups.
>