HOWTO - Discovering and using existing sata raid (eg sil3112)

[dave_blob]

DISCLAIMER: this is my first HOWTO, so ill probably get a lot of the style wrong. I just had huge trouble finding information on this problem, and i thought i should pass it on now ive solved it.

What this is for: People who have a SATA(serial ATA) raid controller, such as the sil3112 controller that comes on the Abit NF-7 S motherboard, and want to use this raid though the controller.
This is *NOT* for people with new, blank hdds. For you it is much easier IMHO to set them up using linux software raid, i believe that there is a howto on this forum already for that.
This *is* for people who need to access raid arrays they have already created, in my case i am dual booting with winxp and i have a large amount of data i need to access in linux.
It is supposed to support these raid controllers:
Highpoint HPT37X
Highpoint HPT45X
Intel Software RAID
Promise FastTrack
Silicon Image Medley


Right, lets get started. These instructions are adapted and fleshed out from the original dmraid(the program used to discover the raid devices) README.

1) download and install your kernel source, you can follow the instructions up to and including 'unpacking your kernel' in the kernel howto wiki
http://wiki.ubuntulinux.org/KernelHowto

2) Lucky for Ubuntu users, the 2.6.8 kernel that ships with warty final already has the device mapper base code! That means for raid-0 people there is nothing to do for step 2, goto 3!
If you want to use raid-0,5 or append, you will need to apply some kernel patches and build a new kernel.
For the 2.6.8.1 kernel they are here:
ftp://sources.redhat.com/pub/dm/patc...table/2.6.8.1/

Apply these patches to your kernel source using something like:
cd /usr/src/linux
sudo cat <directory containing patches>/*.patch > patch -p1

Then build your kernel following the instructions in the wiki link above.

3) Install the device mapper userspace. This is located at ftp://sources.redhat.com/pub/dm/
You might as well get the latest version, which at time of writing is device-mapper.1.00.19.tgz.
Untar this somewhere and go into the directory tar creates.
then run
./configure
sudo make install

4) download the dmraid software
http://people.redhat.com/~heinzm/sw/...urrent.tar.bz2

Untar it, and again go into the directory it creates.
./configure
sudo make install

Almost done!

5) now everything is installed. You just need to make dmraid load on startup and set up the drive mounting.
I didnt make mine load on startup, as i do not need to access my raid drives all that often. So i made a little script to mount them when i need them in my home directory.
Heres how:

You need to find your device name.
ls /dev/mapper/

There will be a few entries that look long and confusing. They are actually just the partitions of your raid drives, prefixed with a complex name. mine looks like
sil_0309402025011
sil_0309402025011_p1
sil_0309402025011_p5

you need to note these down.

make a new file called activateraid in your home directory.
Put this code in it :

dmraid -ay -v
mount -t <fs type> -o users,owner,ro,umask=000 dev/mapper/<your partiton name> /<your mount dir>

and add another line for every partition you have.
Save the file.
chmod 700 activateraid

6) Now test it! run
./activateraid
and all your drives should mount!

!
Hope it works for you. I was so stoked when i finally found this solution. Worth noting is that Ubuntu is the only distro of 3 or 4 ive tried that had the devicemapper code included in a form that was useful for this to work. Yay Ubuntu!