Exchange 2007: Disk considerations

[shane_presley]

We're planning to virtualize an Exchange 2007 environment. It'll be built from scratch -- not a P2V conversion.

I've been reading the forums and some documents, in particular and

But I still have some questions about how to layout the disks. Our ESX 3.5 hosts are connected to a NetApp SAN using fibre. Would the datastore be OK to run inside the VM (on an independant VMDK from the OS?)

I've had other people recommend that the datastore be mounted outside of the VMDKs, perhaps via fcp, cifs, or iscsi?

Thanks

Shane

[bobross]

Quick clarification - by 'datastore' do you mean the Exchange storage group(s)? How many mailboxes, and of what size, do you expect? We run Exchange virtualized already, so I may be able to help with storage group layout.

[shane_presley]

Yep sorry, I meant storage groups. We have 800 users, split into two storage groups, 100GB each.

[Texiwill]

Hello,

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[shane_presley]

Thanks!

Anybody have any insight on how to setup the exchange volumes? Would it be okay to put them "inside" the VM, on an independant vmdk?

[msemon1]

Here is an example on how you might setup your storage:

C: VMDK 40GB (OS) (VM Disk on local ESX Disk)

F: RAW 50GB (SG1 Logs)

G: RAW 100GB (SG1 Data)

H: RAW 50GB (SG2 Logs)

I: RAW 100GB (SG2 Data)

J: RAW 50GB (SG3 Logs)

K: RAW 100GB (SG3 Data)

L: RAW 50GB (SG4 Logs)

M: RAW 100GB (SG4 Data)

N: RAW 50GB (SG5 Logs)

O: RAW 100GB (SG5 Data)

P: RAW 50GB (SG6 Logs)

Q: RAW 100GB (SG6 Data)

R: RAW 50GB (SG7 Logs)

S: RAW 100GB (SG7 Data)

T: RAW 50GB (SG8 Logs)

U: RAW 100GB (SG8 Data)

V: RAW 50GB (SG9 Logs)

W: RAW 100GB (SG9 Data)

X: RAW 50GB (SG10 Logs)

Y: RAW 100GB (SG10 Data)

(Mounting Points May be Used)

Set the RDM's in physical mode and map to your storage. Create an active and passive node for CCR.

[shane_presley]

Interesting. I'm new to RDMs (always used VMFS in the past). But I just did some reading on it. So RDMs would map to phsyical LUNs within my SAN? And I assume the advantage over VMFS is performance?

[msemon1]

Yes, the RDM's will map to physical LUN's in your SAN. I think performance and size limitations may help you decide to use RDM's.

[azn2kew · Accepted solution]

Even though many Exchange 2007, SQL 2005, File servers tend to utilize RDM solution but as you know RDM/VMFS pretty much has the same performance so definitely its not about performance but it would be personal preference. Many people like the flexibility of manage VMFS guest drives and others prefer RDM so it varies. I'm using most of it in RDM mode though but plan physical/logical mode accordingly because each has different usage.

If you found this information useful, please consider awarding points for "Correct" or "Helpful". Thanks!!!

Regards,

Stefan Nguyen

VMware vExpert 2009

iGeek Systems Inc.

VMware, Citrix, Microsoft Consultant

[VMmatty]

I agree with most of the points already stated here. I have multiple environments running Exchange virtualized with CCR and have been happy with the results. The only thing I would change would be to use mount points for your database and log LUNs. It gives you a little bit more flexibility without the risk of running out of drive letters, and it also standardizes your configuration a little better. To each his own though..

What guest operating system are you planning on running for Exchange? There are some support limitations with respect to running Microsoft clusters in virtual machines that you should be aware of. Specifically, using Windows 2008 clusters inside of ESX 3.5 is not supported. Make sure you review the following PDF which explains the requirements for using MSCS in a virtual machine on ESX 3.5.

http://www.vmware.com/pdf/vi3_35/esx_3/r35u2/vi3_35_25_u2_mscs.pdf

RDMs are useful if you want to use SAN based utilities for snapshots and things like that. NetApp in particular has a lot of tools for snapshots of Exchange LUNs so if you want to use those then you should look towards RDM instead of VMDK. That said from a pure performance standpoint VMDK files should be on par with RDMs.

[shane_presley]

Thanks everyone! I'm glad to hear from a performance point of view, I can go either way. I think that you're right -- the NetApp snapshot utilities may make RDM more attractive, but we'll talk to our engineers about that.

As for OS, we'll be using Windows 2003, but thanks for the info on 2008 and clustering.

[msemon1]

I would agree with using mount points. If there was one thing on our installation I would change it would be to use mount points instead of drive letters.