I didn’t know that Dell’s PERC S100/S300 RAID only worked for windows.. no Linux for us. I found this out after buying the Dell T110 server. Booting it said it had 2 SATA 250GB drives in a RAID1 setup. Installing CentOS, it still saw the 2 physical drives instead of just 1 drive in a RAID 1 array. I rang Dell and they let me know this fact.
This was due to code not being released to the public so linux drivers can be written for it or something like that. Some people call this FAKE RAID.
How do I use the Dell PowerEdge S100 and S300 Software RAID controllers with Linux operating systems?
You cannot use the Dell PowerEdge S100 and S300 PERC RAID controllers under Linux and they are software only RAID (fake RAID device) and it only works with MS-Windows operating systems.
Option 1: Disable RAID storage – the S100/S300 controllers by visiting BIOS settings.
You can now use standard software RAID provided by Linux. see here for CentOS 5 guide.
And if the software RAID breaks, here’s the guide to fix it.
Option 2: Use add-on hardware RAID card to server such as PERC 6/E SAS controller with RAID or SAS 6I/R SAS controller with RAID. This means more expense since I had 2 SATA drives and meant getting SAS drives to match the SAS RAID controller cards.
Option 3: There are also hardware RAID cards that do IDE, SATA, eSATA drives, etc. So you can use your SATA drives and build the RAID.
reference: