RAID 10 or RAID 1 x 2 for Hyper-V with AD, EXCHANGE on Windows 2008 R2

We have 2 servers which have 6 SATA 7200 disks inside (each). We want to configure both servers so that they will have Window Server 2008 R2 Enterprise installed and on top of it Exchange 2010 x2 (for 300 people) as one virtual machine and AD x2 as another virtual machine and maybe some additional VM’s (but not that much.

Now we are asking ourselves if it’s better to create 3 RAID groups RAID 1 or (RAID 1 and RAID 10 scenario). We’re looking for performance and protection. Of course SATA drives were choose because of costs and there’s no real option to choose something else.

Idea 1:

• Raid A -> 2 x 1TB (RAID 1) -> C partition for system + D partition for Exchange logs
• Raid B -> 2 x 1TB (RAID 1) -> E partition – all virtual machines
• RAID C -> 2 x 1TB (RAID 1) -> F partition – exchange database

Idea 2:

• Raid A -> 2 x 1TB (RAID 1) -> C system partition + exchange logs
• Raid B -> 4 x 1TB (RAID 10) -> all virtual machines, exchange db

Idea 3:

• Raid A -> 6 x 1TB (RAID10) -> system, all vm’s, exchange db, exchange logs

Idea 4:

• ?

Which of the option is the best? Will having RAID 10 on 4 drives mitigate the problem of putting multiple stuff on one big drive so access speed may be slower if all things at once hit the same target?

Just use one bit 6-way RAID10 array per server, it’s kind of pointless doing anything else as you’re using such slow drives and you’ll lose some IO performance due to virtualisation anyway (you didn’t mention hypervisor or disk access method by the way).

Check more discussion of this question.

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