[CentOS] 4 X 500 gb drives - best software raid config for a backup server?

Fri Feb 20 17:44:34 UTC 2009
Ian Forde <ian at duckland.org>

On Fri, 2009-02-20 at 22:52 +0800, Chan Chung Hang Christopher wrote:
> Bollocks. The only area in which hardware raid has a significant 
> performance advantage over software raid is raid5/6 given sufficient 
> cache memory and processing power.

I'd have to say no on the processing power for RAID 5.  Moore's law has
grown CPU capabilities over the last 15 or so years.  HW RAID
controllers haven't gotten that much faster because they haven't needed
to.  It's faster to do it in software, though it's preferable to offload
it to HW RAID so that any apps aren't affected directly.

I would agree on that cache memory is an advantage, especially when
considering battery-backed cache memory.

But those aren't the only significant areas.  HW RAID allows for
hot-swap and pain-free (meaning zero commands needed) disk replacement.

	-I