Recommend Server config for RAID/ESXi

I am configuring a new server to virtualize, and I'm hoping for a couple of recommendations/suggestions.

I plan on running ESXi from on a USB to keep things simple, along with 2-3 Win2008R2 virtual machines.  But I'm getting confused with the HD configuration.
Traditionally, in a non-virtual world, I have put the OS on a RAID 1 and the Data on a separate RAID 1 (or 5).  I was planning on doing the same here.  

My question is how does this change (if at all) in a virtual world?

What are some best practices?  I have read all sorts of articles/posts on this and other boards and it has helped some.
If I keep two physical arrays (as metioned above) would it be best to put each VM operating system on the first array and the data on the other?
Should I just create one large array and create different logical drives within?

Please forgive my lack or incorrect use of jargon, as I haven't been playing long in the virtual world.  Any other pointers would be most appreciated.


Who is Participating?
Andrew Hancock (VMware vExpert / EE MVE^2)VMware and Virtualization ConsultantCommented:
Just keep the entire virtual machine (OS/ C drive and D:) on the same RAID 10/RAID 5 datastore.

One other item, ensure the datastore (RAID array) you create for ESXi is not larger than 2TB - 512bytes, because this is the maximum supported currently.
Andrew Hancock (VMware vExpert / EE MVE^2)VMware and Virtualization ConsultantCommented:
Firstly check your server you are going to install ESXi on is on the HCL.

Check the VMware HCL (Hardware Compatability Lists) here

Okay, onto your question, you want the best performance for the datastore, that will store the Virtual Machines.

RAID 10 offers excellent read and write performance for VMWAre ESXi datastores. If you can afford and sacrifice the storage otherwise RAID 5 will be apple.

If you are using HP servers, ensure your smart array controllers have Battery Backup Write Cache module to also improve performance of similar with your server, set cache to Read 25/Write 75.
I think that caveat of having battery backed write cache for RAID 5 applies to all controllers, the ones that don't see a dramatic drop in performance without the battery generally enable the write cache at the expense of data integrity should the power fail. You can do that with the later HP controllers but it's very risky to do so except for testing.
jeffcohenAuthor Commented:
Thank you for your responses, they have been helpful.

I'm looking at putting this on a Dell R510, with a PERC controller.  I haven't used the R510 before, but it looks like it will fit the bill.
One of the VM for this server will be an application server -- not very transaction or hard-drive intensive.  I'm thinking of making one of the other VM's a general purpose file server.  Does this alter the question at all?

Andrew Hancock (VMware vExpert / EE MVE^2)VMware and Virtualization ConsultantCommented:
you could probably use RAID 5.

Dell R510 ok
Question has a verified solution.

Are you are experiencing a similar issue? Get a personalized answer when you ask a related question.

Have a better answer? Share it in a comment.

All Courses

From novice to tech pro — start learning today.