Quote Originally Posted by Robotbeat
Well, if you are running lots of virtual machines and don't care too much about wasting capacity, I would focus on seperating your sequential accessing luns from your random access luns. Each sequential-access-pattern lun should get its only small raidset, probably just RAID 1 unless you need higher than about 50MB/s (if you need higher performance, you'll need to use a RAID 10 or something).

Then, if you have a few virtual machines that have mostly a random access pattern, then put them all in one big raidset. Use RAID 10 if you can afford the space, but with lots of the hardware raid controllers (esp. Areca and other things that use the IOP chip), RAID 5 or RAID 50 or even RAID 6 aren't really going to cause you to lose too much performance.
Hi Robotbeat, Thanks a lot for the advice!

I'm learnig as I go and you seem to have a lot of experience here so please correct me as necessary...

This storage server and the VM servers are going to be used to consolidate all out internal IT servers... so a couple of domain controllers, one file server (arounf 80GB of users data), one exchange server, one database server with a couple of small databases, one BES and 4 or 5 other different application servers... So if I understand the concept right, most of them if not all should have a random access pattern.

So that is why I was going with the 1 big raidset as you sugest. This is my logic: if I am going to use 1 big raidset for all VMs, I need it to be very fast and the only way to combine both RAID controllers performanse is to use Open-E Software RAID 0 on top of whatever hardware RAID level I decide to use on them, that is why I propossed those 3 configs... either a 50 on each controller, a 10 on each controller or just a bunch of 1s...

I am leaning towards options 2 or 3 but this is where I don't have a clue of what would be better... if having a Software 0 over a Hardware 10 or a Software 0 over several Harware 1.

BTW, the controllers I have (Intel SRCS28X which is the same as the LSI Megaraid 300-8X) do not support RAID 6 so that is not an option.