Ok I noticed a lot of people are changing their RAID setup via SSH, but there is actually quite an easy way to do this via the OVH Manager which will take you no more than a minute or two. I got this idea from another post on this forum but seeing as it was rather abandoned and did not go into detail too much, I decided to rewrite it with details and screen shots
1. Login to the OVH Manager, choose the dedicated server you wish to change the RAID config on, go to 'Services', and click on 'Reinstall/Change OS' and choose the operating system you want. I hope by now you realize you will need to reformat your hard drive, so make a backup if you need to.
2. When you get to stage 2/3 Choice of the Partitions, select the third option which says 'Other Layout of partitions' and from the dropdown list choose 'RAID Software'.
3. Now we're in the third and last part of the setup process in which we will choose the sizes of the partitions, of which there have to be at least three. Setup your partitions the same way you see below, or if you'd like, you can always add more partitions with different sizes. It's up to you
The Partitions are as follows:
a. Partition 1, Filesystem: 'ext3', Mountpoint: '/', Size: 20,000MB
b. Partition 2, Filesystem: 'swap', Size: 1024MB
c. Partition 3, Filesystem: 'ext3', Mountpoint: '/home', RAID Type: '0', Size: 'All that's remaining'
The Result
After I completed my installation (Ubuntu Desktop) I took this screen from within my /home partition.
UPDATE: My screen shots have gone down, I will repost them once I get home later today