[CentOS] Hardware RAID Controller

From: Lee W <centos-list at unassemble.co.uk>
> Ebay UK didn't turn up much (althought there was a few in the US). 
> However just tried googling a bit more and I've come across a 3ware 
> Escalade 7506-4LP for about �200.00 which supports upto 4 drives so that 
> should be suitable for my purposes, plus it looks quite small (being a 
> Low-Profile card) so should fit in the rack as well. 

You can even take the bracket off as long as you can mechanically secure
it another way.

> Okay I'm getting a bit over my head now.  Anyone see any problems 
> putting 2 of these in the same machine.

3Ware has always supported up to 4 cards in a system.
Just make sure the firmwares are the same for each model
or expect issues with drivers.

> After a few other comments I was thinking of trying 2 x RAID-1's.

Why not a 4-drive RAID-0+1?
It's far better to do it on a single card.

Unless you are thinking of (2) RAID-1, each on their own PCI-X channel,
and then a RAID-0 LVM2 stripe across them?

In reality, you're really gotta get up to 8 drives in RAID-0+1 before
you're going to saturate the 0.5GBps 64-bit @ 66MHz PCI bus.

And in all the 1U systems I've seen, I've only seen a maximum of (2)
PCI-X channels.  You'll want to use one dedicated to your NIC.



--
Bryan J. Smith   mailto:b.j.smith at ieee.org