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gauravmahajan
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vSphere Replication to replicate a SQL Cluster?

Hi,

Does anyone know if there are any issues when using vSphere Replication to replicate a SQL cluster as part of an SRM solution for DR?

Thanks in advance for your help!

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vbrowncoat
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vSphere Replication supports replicating virtual mode RDMs. They are converted to VMDKs upon recovery though (which would mean that they likely wouldn't work on an ongoing basis for a SQL cluster).

If you could use regular vmdks with your SQL cluster (which would mean that you weren't using the multi-writer capability of physical mode RDMs) you could replicate it with vSphere Replication. The requirements of VR are the same regardless of the workload running on it. Here is the quote from the kb:

"vSphere Replication does not work with virtual disks opened in "multi-writer mode". MSCS cluster virtual machines are configured with virtual disks opened in "multi-writer mode," so vSphere Replication will not work with a MSCS configuration."

The only way that I can see vSphere Replication protecting a SQL cluster using physical mode RDMs is in the one-time situation that the articles outline, not on an ongoing basis. For that you would need to look at array-based replication.

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rcporto
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See: vSphere Replication FAQ (2005776) | VMware KB

Does vSphere Replication support MSCS clusters?

vSphere Replication does not work with virtual disks opened in "multi-writer mode". MSCS cluster virtual machines are configured with virtual disks opened in "multi-writer mode," so vSphere Replication will not work with a MSCS configuration.

So, you will need to use ABR (array based replication) to protect your MSCS clusters.

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Richardson Porto
Senior Infrastructure Specialist
LinkedIn: http://linkedin.com/in/richardsonporto
gauravmahajan
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Hi Richardson

Thank you very much for your prompt reply to this thread as well as your guidance. The following blog post and thread however seem to indicate otherwise:

http://vmnomad.blogspot.com/2015/09/windows-failover-cluster-migration-with.html

[SOLVED] Migration of Microsoft Clusters (with RDM drives) between datacenters - VMware - Spiceworks

Edit: Just to be clear, we are working with Windows Server 2008 R2 & SQL Server 2008 R2

Not sure if I am missing something here (which I might be Smiley Happy)

Thanks again!

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vbrowncoat
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That could work, just note that they aren't replicating a VM with physical RDMs as they are removing them or converting them to virtual mode.

gauravmahajan
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Thank You  gs_khalsa!

Sorry, I am a little confused now.

Just so I understand it correctly, are you saying that vSphere Replication is going to work for a SQL cluster as long as virtual mode RDM disks are being used?

And if so, how does that compare to the guidance mentioned in this article then: https://kb.vmware.com/selfservice/microsites/search.do?language=en_US&cmd=displayKC&externalId=20057...

What if VMFS disks are being used?

To be additionally clear, I am talking about a continuous replication scenario where we plan to continuously replicate the VMs to a DR site vs. the one time scenario that the article I referred to in my response earlier points to.

Thanks again!

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vbrowncoat
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vSphere Replication supports replicating virtual mode RDMs. They are converted to VMDKs upon recovery though (which would mean that they likely wouldn't work on an ongoing basis for a SQL cluster).

If you could use regular vmdks with your SQL cluster (which would mean that you weren't using the multi-writer capability of physical mode RDMs) you could replicate it with vSphere Replication. The requirements of VR are the same regardless of the workload running on it. Here is the quote from the kb:

"vSphere Replication does not work with virtual disks opened in "multi-writer mode". MSCS cluster virtual machines are configured with virtual disks opened in "multi-writer mode," so vSphere Replication will not work with a MSCS configuration."

The only way that I can see vSphere Replication protecting a SQL cluster using physical mode RDMs is in the one-time situation that the articles outline, not on an ongoing basis. For that you would need to look at array-based replication.

gauravmahajan
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Thank you! So sorry for the late response. I was checking further details with the storage and DB teams. While i don't have a response from them yet, I believe your answer points me in the right direction. Thanks again for all your help gs_khalsa & ‌!

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