one big array, or a boot array and a (less big) array ?

[Scott Long]

Arone Silimantia wrote:
> I have a system with 8 drive bays.  I have 8 250 GB
> disks.
> 
> I would like to just create one giant raid5 array in
> my adaptec hardware raid controller of size 1.75 TB,
> and just make my partitions (/, /data, /var) on that
> big 2 TB array.
> 
> But I feel like I have heard suggestions on this list
> before that one should have a separate array just for
> the boot and userland, and that the big monster array
> should be separate from that.
> 
> So instead, should I take two of the 8 disks and make
> them a mirror, and put boot/userland on there, and
> then  make a raid5 out of the remaining 6 ?
> 
> Or does it not matter at all ?
> 
> If one is better, why ?  Thanks.
> 

If reliability is your highest priority, then you should create (as you 
describe above) a 2 disk RAID-1, a 5 disk RAID-5, and assign the 8th 
disk as a global hot-spare.  Putting 8 SATA disks into a single 
enclosure has implications for cooling all of those drives, which in 
turn has implications for drive life.  If I were doing it, this is
exactly what I'd do.

Scott