Hyper-V Core Performance RAID 5 vs. RAID 6
Posted on 2013-06-25
I am spec'ing out new servers for a couple of regional offices. On each server (Dell PowerEdge T420) I plan to run MS Server 2012 Hyper-V Core and then virtualize 4 servers: an RODC, print server, file server (for IT files), local image server, and a win 7 test machine.
I am looking at using a PERC H710 with 1GB Cache and two arrays:
1st: RAID 1, 2 146GB SAS 15k 6Gbps (hyper visor)
2nd: RAID 6 5 300GB SAS 15k 6Gbps (all vm's)
I am going with two quad core processors and was planning on 32GB RAM.
My question is this:
Is RAID 6, with it's two write operations, best suited here? This is a regional office and really only uses their local server to connect to headquarters via WAN - hence the RODC. The only thing that I need locally is a print server and the file server that will be used by IT when we need to push out 3rd party updates. I think that RAID 10 might be a bit faster- but the regional offices are far from HQ and hard to service in the event of an emergency so I tend to want to go with redundancy over performance so long as the hit isn't to bad.
From what I have read here so far- it seems to me as though I can expect the same or better read times from R6 but writes will be slower by a constant value due to the second parity disk. RAID 10 on the other hand will be faster, but require 2 more disks to get the same space if I want to have a hot spare. If I use RAID 6 and have a failure- I can always wait until after business hours to do the rebuild as I have enough redundancy.
Realizing that this may be a bit of religious debate- I am interested to hear what the community at Experts Exchange think.