Support for Microsoft Cluster Server (MSCS) in 3.5 update !
April 2nd, 2008
I received an email stating the following:
Microsoft Cluster Server is supported with VMware ESX 3.5 Update 1. Support is similar to ESX 3.0.1 with the following additions:
- Both 64 bit and 32 bit Windows 2003 guests are supported with MSCS.
- Boot from SAN for VMs using MSCS is now supported.
- Majority Node Set clusters with application-level replication (for example, Microsoft Exchange 2007 Cluster Continuous Replication (CCR)) is now supported.
For details regarding MSCS support, including a number of important restrictions, please see the document “Setup for Microsoft Cluster Service.” For information concerning supported storage arrays, refer to the Storage/SAN Compatibility Guide for ESX Server 3.5 and ESX Server 3i.




April 4th, 2008 at 09:11
Hi
Any news from your sources if the 64 bit cluster support will be added to ESX 3.02 releases (3.02 update 2 maybe?) or just to the 3.5 release?
Cheers
David
April 4th, 2008 at 09:37
No news yet, who knows…
April 5th, 2008 at 21:03
[…] Duncan and Thomas, ESX Server 3.5 Update 1 will provide support for Microsoft Cluster Server (MSCS). […]
April 8th, 2008 at 08:45
Hi Duncan -
Just a quick question mate.
Why would an architecture require MSCS if HA/DRS in enabled?
What sort of env variables might dictate MSCS as necessary?
I cannot think of a reason to use MSCS w/ VMware Guest OSs now that HA Clustering has been introduced? Can you mate?
Best regards,
Jason
April 8th, 2008 at 20:05
Jason,
What if you have an application that required high uptime? What if a VMware host crashed due to hardware failure and your VM was running on it?
HA will start the VM from other VMware host but there will be downtime involved. With MSCS, you can have 2 VMs separated by rules so unless both VMware hosts crash at the same time, you will always have a VM running and with MSCS, it can keep resources available to users.
Thanks,
Bhargav
April 8th, 2008 at 20:36
Scott wrote about this a couple of days ago shortly. MSCS is stateful clustering, in other words the service keeps on running when a failover occurs. HA is stateless clustering, the VM will be shutdown and started on another node. So the service will have down time for sure.
In my opinion and experience there’s a down side to both options… Stateful doesn’t provide you with the flexibility VMware can provide you with, and besides that it isn’t completely stateful anyway. In production environment you’ll often see more downtime for stateful clusters than you would expect.
on the other hand, HA will never provide you with stateful clustering… but continous availability will in the feature. so we will just have to wait and see.
For an ESX environment virtual MSCS clustering is something I personally try to avoid.
April 10th, 2008 at 13:23
Anyone an idea where I can download Update 1 for ESX server 3.5? Is it yet available?
The release notes of ESX server 3.5 from the vmware site are still clear:
“Microsoft Cluster Service (MSCS) is not supported in this release of ESX Server.”
Thx,
Vegeta
April 10th, 2008 at 13:32
Not yet available, should be available today according to the vmware website a week ago… so just a matter of time.
April 14th, 2008 at 14:50
It’s there waiting to be downloaded.
”
Support for Microsoft Cluster Service (MSCS)
VMware ESX Server 3.5 Update 1 supports Microsoft Cluster Service. Support is similar to ESX Server 3.0.1 with the following additions:
- Both 64 bit and 32 bit Windows 2003 guests are supported with MSCS.
- Boot from SAN for VMs using MSCS is now supported.
-Majority Node Set clusters with application-level replication (for example, Exchange 2007 Cluster Continuous Replication (CCR) is now supported.
“
April 22nd, 2008 at 15:38
@Duncan:
Are there any particular reasons you try to avoid mscs clustering (of Exchange, for example) in a virtual environment? Are there any significant (technical) drawbacks?