RAID0 for speed. Also there is NO option in OVH web interface to do Debian install to RAID0 (and I I have bought server with same size disk then I should have one..Im paying for that.)
Dunno how you guys do it, but no self respective computer technician will make you RAID array with even different brand drives here in Finland. All my RAID arrays at home(0,1,5) have all drives same make and model(even same FW version(that is not nessesary tho).
And I just start to think about that mishmatch drive install from last summer ONLY after that "marks" person from OVH adivice to email about it. That was just too funny..If I told you whole story what happen last summer. No one from OVH did not knew anything about anything(exept price oc). And after I had send all HD info from broken drive from recue mode it took over week to anyone even reply to me. I had strong feeling that they did not even know what hard drive is in Roubaix datacenter..it really was that funny.
I got 3 week compensation from server price(they said that it is extremely rare) cuz it took them that long to even get that different size disk.
Now they change the drive, so there is 2 same size drives, cuz they noticed that its imposible to install Debian to RAID0 from web interface.
Its really not difficult to set up raid0 on two different size drives. Google is your friend.
Hint: Use partitions.
I never said it was imposible, but you cant make it from OVH web config, nor anyone from OVH cant assist you even they sell those servers RAID0/1 . Its like bying a new car and after that you need to start searching engine for it.
Only way to use different size disk in RAID0 was to start install in RAID1 mode then make new partitions, but you cant move OS from RAID1 partition to new RAID0 one. So you dont get what you bought. With same size drives even OS is in RAID0 partition.
And IMO. if OVH sells these server RAID0/1 but one can do only RAID1 install(an there is no one to have even link to any quide) = ITS NOT RIGHT nor legal. If I have bought server with "straight RAID0 support from OVH" they need to sell what they advertise.
But like I said at least here (Finland) we do quality work. I have never installed different brand drives to even cheap desktop computer let alone much more expensive servers. And personally I have one spare HD (same make/model) for my RAID5 array(only array atm. with more than 2 drives. Maybe others just make sloppy work.