[Okta Webinar] Learn how to a build a cloud-first strategyRegister Now


RAID config small hyperv setup

Posted on 2015-02-04
Medium Priority
Last Modified: 2016-12-08
I'm setting up a new Windows Server 2012 R2 server.  The server has 3 x 600 GB 15K SAS hard drives in a RAID-5 array plus one hot spare.  My plan is to setup a Hyper-V host and then create two or three VMs (depending on whether the customer wants to pay to license the 3rd/4th instance).  The customer environment is relatively small.  Initially, there will be 6 users on the network with a 7th user connecting remotely.  There may be 10 or 12 users max within two years.  The workloads are Hyper-V by itself on the host O/S, Active Directory (guest O/S), Remote Desktop Services (guest O/S) and possibly applications/data in a 3rd guest O/S.  If we stick with only 2 VMs, the applications and data would have to go on one of the other two guests.  In my research of best practices, several people recommend putting the host O/S on a RAID-1 array and then putting everything else on a separate array, such as a RAID-5 array.  I'm wondering if this type of setup is really necessary in a smaller environment (i.e. 10 users) and if I would even notice a performance difference if I just did everything on a single RAID-5 array.  My server already has the RAID-5 array as well as Windows Server 2012 R2 Standard installed, and right now I only have a total of 4 hard drives.  I'd like to proceed with my original plan, but wanted to get some advice from the "Experts" on whether or not this would be a big mistake.  Thanks.
Question by:AdamNV
  • 2
LVL 124
ID: 40589565
We usually, see a

Data/VMs - RAID 5 (or better RAID 6) - RAID 5 has no place in production these days, as disks fail, RAID 6 gives better resilience!

Especially you find, if ALL disks are the same batch, they tend to fail all at the same time.....especially when you replace a disk in RAID 5, to rebuild, other disks start to fail, and your RAID 5 RAID array is worthless.

So RAID 6 better resilience!

see here, Statement from DELL!


Author Comment

ID: 40589596
I understand your concern about redundancy, and it's a valid concern.  Given my set of circumstances, however, if we assume for a second that I would be able to recover from a single hard drive failure in the RAID-5 array (either with the hot spare and/or replacing the failed drive), my question is really more about performance concerns.  How relevant is the following statement for the setup in an environment with 10 users:

"You must not store Hyper-V virtual machine files on drives used by the Operating System. It is because of the I/O operation. Drives, where the system files are stored, are accessed by the system processes continuously and this might cause delay in processing the Hyper-V tasks."
LVL 124

Accepted Solution

Andrew Hancock (VMware vExpert / EE MVE^2) earned 2000 total points
ID: 40589605
I would agree, and split the OS from Data (VMs).

on different disks, RAID Arrays. (not partitions!)
LVL 40

Expert Comment

by:Philip Elder
ID: 40589868
Our base configuration is an R1208RPMSHOR with 32GB ECC, 1GB Intel RAID with NV Cache, and 8x 300GB 10K 2.5" SAS drives. They would be configured in RAID 6 with two logical disks:
 LD0 Boot: 60GB
 LD1 Data: 1.6TB

Since 300GB 10K SAS drives are very inexpensive we get enough storage but most importantly we get the IOPS we need to run any virtual environment.

RAID 5 is Anathema. That is, it is a no-no. Search "Punctured Stripe" for an idea of why.

The smallest setup that we have is on an X3470 with 32GB ECC and a 1GB Intel RAID and battery backup. That system came with six drive bays so we have six 600GB 15K SAS drives configured in a RAID 6. We had RAID 10 but one drive dropped and then about five minutes into the rebuild its pair dropped so we lost the server. RAID 6 all the way.

If the server has 6 bays then install 6 drives. If it has 8 then install 8. Maximum IOPS, even with 2 VMs, is the goal as the disk subsystem is almost always the bottleneck.

Featured Post

Free Tool: Subnet Calculator

The subnet calculator helps you design networks by taking an IP address and network mask and returning information such as network, broadcast address, and host range.

One of a set of tools we're offering as a way of saying thank you for being a part of the community.

Question has a verified solution.

If you are experiencing a similar issue, please ask a related question

In this article we will learn how to backup a VMware farm using Nakivo Backup & Replication. In this tutorial we will install the software on a Windows 2012 R2 Server.
In this article will go through how to backup a vPostgres DB from a broken vCenter Appliance and restore to a new vCenter Appliance.
In this video, we discuss why the need for additional vertical screen space has become more important in recent years, namely, due to the transition in the marketplace of 4x3 computer screens to 16x9 and 16x10 screens (so-called widescreen format). …
With the advent of Windows 10, Microsoft is pushing a Get Windows 10 icon into the notification area (system tray) of qualifying computers. There are many reasons for wanting to remove this icon. This two-part Experts Exchange video Micro Tutorial s…

872 members asked questions and received personalized solutions in the past 7 days.

Join the community of 500,000 technology professionals and ask your questions.

Join & Ask a Question