RAID 5 via mdadm

Finally got the SATA PCI cards (SIIG SC-SA4011) in at work today so I was able to go ahead and build the new RAID array.

The first hurdle was to figure out what chipset the SATA cards use, but after removing the SIIG sticker I found a nice SiI 3114 chip which is well supported via the sata_sil 2.6x kernel module. After enabling it in the kernel (CONFIG_SCSI_SATA_SIL) along with SCSI disk support and rebooting I got a nice trio of disc devices (/dev/sd[abc]) and was able to move on to partitioning.

As I noted in my previous Raid 1 post, it’s pretty essential to type the RAID partitions as Linux raid autodetect (cfdisk screenie, cfdisk type screenie) so udev sets up the device nodes correctly. Other than that, just make sure you have at least three disks with partitions of approx. the same size and you should be ok. In my case I just created one big partition on each of my three drives since this is their only purpose in life…

All that needs to be done to create the array is run mdadm --create /dev/md3 -l 5 -a --raid-devices=3 /dev/sd[abc]1 and you should see a new array being reconstructed in /proc/mdstat…