[Last Call] Learn how to a build a cloud-first strategyRegister Now


RDM and VMFS with ESX 3.5 for CCR Cluster Exchange 2007 on Windows 2008

Posted on 2009-04-29
Medium Priority
Last Modified: 2012-08-14
We will use CCR CMS with Windows 2008 ent. failover cluster for Exchange 2007 SP1.  I read a lot of books and documentation.  But it's not clear to me whether it's better to keep using  the VMFS disk for the guest OS and Exchange or using Raw Device Mapping.  Raw Device Mapping datastores will be used for all Exchange storage and databases (mailbox, public folders)

To make myslef clear, here is what I think is best practice, but feel free to correct me:

on the C: drive (VMFS) WIndows 2008 is installed
on the D: drive (RDM) Exchange is installed
on the E: drive (RDM) Transactional Logs
on the F: drive (RDM) Exchange databases

Thank you
Question by:quadrumane

Accepted Solution

markzz earned 1000 total points
ID: 24262934
Although RDM in theory may give better performance If you can get the performance you require from a VMFS I'd suggest using VMFS for simplicity of backup and DR.
As far as clustering just wait for ESX version 4, FT will solve your clustering, unless you want the clustered partner to be in a separate physical location.
Version 4 will be released in 3 weeks.

Author Comment

ID: 24263141
The Failover Cluster must interract with the SAN, not see the disks as if it was  local disks.  So why suggesting VMFS ?  The cluster is local, but later SCR will be used to add another point of failure.  

Unfortunately I have a deadline.  But in what FT can solve my clustering ?  What is FT ?


Expert Comment

ID: 24265441
The new Fault Tolerance in the new VMware vSphere product.  protect a server and have another virutal server running in complete lockstep for zero downtime, zero data loss availability.  Check out my blog post the videos should explain it http://www.virtualpro.co.uk/2009/04/27/vsphere-fault-tolerance/

Trying to understand your problem here,  you have a SAN,  you want to use Microsoft Windows 2008 Enterprise failover clustering for protection.  Are you using two Windows 2008 Enteprise virtual machines to connect into the SAN for the failover cluster?
Making Bulk Changes to Active Directory

Watch this video to see how easy it is to make mass changes to Active Directory from an external text file without using complicated scripts.


Author Comment

ID: 24265521
Thanks for the article on your blog.  I do use 2vCPU for Exchange but I could use one (according to the tests at the Delltechcenter Exchange 2007 is faster with 1 vCPU for 500 heavy mailboxes)

This new feature will simplify  HA management.  No more Windows cluster.

I have 3 SAN, I want to use Microsoft Windows 2008 Enteprise failover clustering for Exchange 2007 (CCR)

On 2 SAN I have 2 LUN of 1TB each available for RDM.  But I don't know if it's better to use RDM disks for the Guest OS too.   I'm not sure about Vmotion when all RDM disks are used for a VM.

But the Windows failover cluster has to be SAN aware, so this is why I have to use RDM.  

LVL 19

Expert Comment

by:vmwarun - Arun
ID: 24267792
What mode are you trying to use for RDM ? Physical Compatibilty Mode or Virtual Compatibility Mode ?

The benefits of choosing VC Mode is you will be able to use the snapshots feature while the PC Mode does not allow you this.

Please keep this in mind while using RDM.

Assisted Solution

davismisbehavis earned 1000 total points
ID: 24268319
Just following up on arunraju's point

You can use Physical Compatibility mode for your RDM's if your wanting to use native SAN tools to snapshot LUNs, etc.  However using physcial compatibility mode means you can't use the VMware snapshot capability.  Your decision depends on whether you want to use your native SAN management / backup tools.

With regard to your main issue,  you'll have to do some research on the RDM with Vmotion question.  I had a quick look and RDM's and Vmotion doesn't appear to be to much of an issue and is generally supported.  However Vmotion, RDM's and clusters is where it get's tricky and is where you may possibly find it is not supported.

Get across to the Vmware communities site and raise it as a question,  there are so many Experts over there who will have been through this exact same thing before.  You'll wither find something that'll point you in the right direction or someone will tell you exactly where you stand and what you can and cannot do.

Good Luck


Featured Post

Creating Active Directory Users from a Text File

If your organization has a need to mass-create AD user accounts, watch this video to see how its done without the need for scripting or other unnecessary complexities.

Question has a verified solution.

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

Are you looking for the options available for exporting EDB files to PST? You may be confused as they are different in different Exchange versions. Here, I will discuss some options available.
With so many activities to perform, Exchange administrators are always busy in organizations. If everything, including Exchange Servers, Outlook clients, and Office 365 accounts work without any issues, they can sit and relax. But unfortunately, it…
This video shows how to quickly and easily add an email signature for all users on Exchange 2016. The resulting signature is applied on a server level by Exchange Online. The email signature template has been downloaded from: www.mail-signatures…
Exchange organizations may use the Journaling Agent of the Transport Service to archive messages going through Exchange. However, if the Transport Service is integrated with some email content management application (such as an antispam), the admini…
Suggested Courses

825 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