raid on ubuntu

There are 3 different types of RAID array:
- Sofware raid requires no additional hardware at all. It is set up, configured and managed at OS install time or possibly later.
- Hardware raid requires a hardware raid card. Calculations for parity, etc are done by jiaohuan/'>the raid card. It is set up in jiaohuan/'>the hardware raid controller and is transparent the operating system - the OS never sees separate disks; the array is presented the OS as a single disk.
- So called "fake raid" uses a hardware card with a bios on it. There is usually a bios based setup utility, but the actual raiding is managed by an operating system driver. Without the driver your operating system will see multiple drives. Calculations for parity and such are done by the CPU. This is what you have.

Fake raid on linux needs to be set up by using dmraid and requires a slightly fiddly installation of booting into a live CD then installing packages manually.

Running dmraid -l show that your chipset is supported for RAID 0,1, 0+1 or 10. NOT raid 5, unfortunately. However, you do not need any other packages/drivers to implement dmraid array.

cheshacat@chesha:~$ dmraid -l asr : Adaptec HostRAID ASR (0,1,10)ddf1 : SNIA DDF1 (0,1,4,5,linear)hpt37x : Highpoint HPT37X (S,0,1,10,01)hpt45x : Highpoint HPT45X (S,0,1,10)isw : Intel Software RAID (0,1)jmicron : JMicron ATARAID (S,0,1)lsi : LSI Logic MegaRAID (0,1,10)nvidia : NVidia RAID (S,0,1,10,5)pdc : Promise FastTrack (S,0,1,10)sil : Silicon Image(tm) Medley(tm) (0,1,10)via : VIA Software RAID (S,0,1,10)dos : DOS partitions on SW RAIDs

If you wish to set up a RAID array on your existing hardware, use this howto, it may look intimidating but it's actaully quite easy. It's pretty much copy and paste after a while but I do recommend you read whats going on and take your time to understand it, it will be worth it in the long run:

It's for dapper and there are one or two bits that have changed for more recent versions, but if you read the comments carefully at the end, everything you need to know is there:

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1) "I used the package ubuntu-standard rather than ubuntu-base since this and ubuntu-minimal (which is already installed by this point) obsoletes it."

2) "During grub install the line

cp /lib/grub/$SETUP_CPU_GRUB/* /boot/grub/

fails because now the stage files are put in /usr/lib/grub/$SETUP_CPU_GRUB

"

3) "I used the package linux-generic rather than linux-$SETUP_CPU_UBUNTU since this obsoletes most of the linux kernel installs."

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One other caveat is that you need to manually edit /etc/group and add your user to the "admin" group or you won't be able to admin things in gnome.

Good luck!

Edit: for what it's worth, RAID 5 pretty much sucks. Since you have 6 disks, I would consider giving the space over to a RAID 10 setup, it's well worth the difference.