RAID disk “group” and virtual disks setup

Question

We will be setting up a system as the following (on a Dell PE R510 with a PERC H700 (LSI2108) 512MB-BBU SAS HBA):

Disk Bay 1
2xHDD RAID 1 Virtual disk A

Disk Bay 2
8xHDD RAID 10 Virtual disk B
4xHDD RAID 10 Virtual disk C

Now with the PERC controller, you can create "disk groups", then virtual disks within those groups. The only requirement with disk groups is that all virtual disks within that group are of the same RAID level. So, with respect to the two virtual disks in bay#2, is there a benefit in creating one group to house both virtual disks or should we create two separate groups, one for each RAID 10 VD? Anyway, which is better, or does it even matter?

Answer 1

Which is better and whether it matters depends on what you want to do with the disk capacity.

If you need to totally isolate the IO between the three virtual disks then having three RAID groups makes sense. If you have IO requirements for individual volumes that will benefit from being able to make use of more peak IO\Bandwidth than can be delivered by 8 disks then you may be better off making one larger RAID group (to get all the spindles into one pack) and splitting that up into the multiple virtual disks.