[plug] Raid 0 software? hardware?

[Craig Ringer]

WolfBite wrote:

>cool, thanks
>
>at the moment I'm still trying the hardware raid, as
>this works with xp & linux at the same time.
>  
>
The hardware RAID you're taking about is almost certainly not real 
hardware RAID. Lots of "hardware RAID" is actually just a standard 
ATA/SATA controller on the motherboard with a few BIOS hooks to let the 
BIOS see the RAID array as a single bootable drive. The RAID is done by 
OS drivers - it's just software RAID. They do have the advantage of 
hardware RAID in one way - the array format is OS independent. 
Unfortunately, your RAID array won't be portable to different systems 
(except maybe with the same motherboard RAID chipset).

>just surprised that the speed difference is not as
>much as people said it would be :(
>
You're very dependent on the drivers and the particular controller in 
the semi-hardware RAID provided by most chipsets built in to motherboards.

I'm also kind of concerned that you mention that you're using RAID 0. 
RAID 0 across four disks is a death sentence to your data, even with 
high quality "enterprise" SCSI/SATA disks. With "consumer" level 
ATA/SATA disks I'd expect total loss of all data on the array within a 
year - at least going by my luck with disks.

RAID 0 means that if any disk fails, you lose all the data on the array.

You probably want to look into using RAID 10 instead; that can be 
thought of as essentially the same as taking two RAID 0 disk pairs and 
running RAID 1 over them. You can lose any one disk and be able to 
recover, or two if you're lucky and the failed disks are in the same 
RAID 0 pair. MUCH safer - but you only get half the storage capacity out 
of it. I think it's a bit faster too, though.

--
Craig Ringer