On 3/9/2011 10:47 AM, Peter Peltonen wrote:
>
>> I recently had a problem like that with a Dell box. The trick is that with
>> a hardware controller, it supercedes software RAID. What you need to do is
>> go into the firmware controller configuration on boot, before you get to
>> grub, and make sure everything's visible and correct. The controller can
>> see the drives, but not present them to the o/s if you don't.
>
> Hmm, I am not sure if I understand you correctly: are you saying that
> in the firmware configuration there might be an option that makes the
> disks invisible for the OS? This sounds a bit strange and I wonder
> what such config could be...
Some controllers want to map arrays to volumes and present the volumes
to the OS instead of drives, so you have to go through the motions of
assigning the resources to volumes and initializing them even if you
only want one disk in the array or volume.
> Or are you suggesting that I should put the controller in "JBOD mode"
> and then use software RAiD instead of hardware RAID? I would not like
> to go with this option as I think the performance would suffer this
> way?
Depending on the raid level there may or may not be a performance
difference, but the point is you have to configure the controller and
drives they way you want them before they will show up at all.
--
Les Mikesell
lesmikesell at gmail.com