[ILUG] Highpoint Sata RAID

[Niall O Broin]

On 23 Mar 2005, at 10:53, Paul Jakma wrote:

> Interestingly, the Promise SX4 SATA cards actually /are/ hardware 
> RAID. At least, they have onboard RAM and a XOR engine to be able to 
> accellerate RAID-5. The RAM allows the OS to only have to copy data 
> across the PCI bus once, and then issueing the disk transaction from 
> the card-local data.
>
> Sort of a hardware-accellerated card.

Hardware assisted RAID maybe? But still, host drivers needed. Let me 
modify my definition of hardware RAID then - hardware RAID is where the 
operating system has NO involvment in doing the actual RAID work (it 
will of course have to have drivers for the card) and the OS sees as 
disks only the RAID volumes provided by the controller, no matter what 
the physical disk layout is.

> It doesn't get involved in the details of managing RAID-5 - left for 
> OS - but does provide the hardware needed for fast RAID.
>
> Linux md doesnt make use of that onboard hardware yet though.

So you can use the not very well tested Promise Linux driver (if there 
is one for that card) or md without hardware assistance. I know which 
I'd use.



Niall