Hello Uptime Readers,
We have seen a lot of questions lately relating to SRM support for Windows 2008 and there seems to be a lot of confusion out there so it seemed like a good time to maybe write a short blog to try and clear things up.
When you are working with or implementing SRM 4.0 and are asking questions or looking for information on operating system support the first thing you need to understand that will hopefully make things simpler is in what function will the operating system be used, there are two choices really:
It will be the operating system we use to install the SRM server (or SRM client plug-in) in to
It will be the operating system we use in the virtual machines we want to protect with SRM
Let’s take each in turn.
When deploying SRM you need two SRM servers, one at each site. The SRM server will in nearly all cases be deployed into a virtual machine itself but this virtual machine is not classed as a protected virtual machine as its role is simply to run the SRM server at that site and it will not normally be placed on replicated storage as there is no need to replicate an SRM server as the other site also runs an SRM server.
More frequently customers are now wanting to deploy SRM into Windows 2008 virtual machines. Before you do this you should review the SRM Compatibility Matrix.
Specifically review the section “SRM server operating System Compatibility” in this section you will need to be aware that although both Windows 2008 x86 and x64 are listed you should review the table carefully and understand that at time of writing the following statements are true:
If you want to use Windows 2008 to host your SRM Server note it is currently ONLY supported on the x86 (32bit) editions of Windows 2008 running SP1 (support for R2 editions will be reviewed on an ongoing basis). UPDATE: SP2 x86 support is now available!
If you want to use Windows 2008 to run your vSphere client and therefore install the SRM vSphere client plug-in note this is supported on the x86 and the x64 editions of Windows 2008 running SP1 (support for SP2 and R2 editions will be reviewed on an ongoing basis)
Protected Virtual Machines
Now that we have covered the SRM server what about the virtual machines you actually want SRM to protect, those virtual machines running your production workloads and applications that are sitting on your replicated storage.
As with the SRM server if you review the SRM Compatibility Matrix you will find the following section:
If you are looking for clarification for Windows 2008 support (though you could use this example for any GuestOS) you need to understand what each of the above paragraphs is telling you. First I think we could improve the clarity here and this is something we will review internally for the next documentation update. If we start with “Guest Operating System Support” the statement is “SRM 4.0 supports all guest operating systems supported by vCenter 4.0”.
What does this actually mean? From the SRM perspective what this is actually telling you is that SRM can “protect” any guest operating system that is a supported guest operating system on the vSphere 4.0 platform. You can review the full list of supported guest operating systems for vSphere here by setting:
Product Name = ESX
Product Release version = ESX 4.0
OS Use = Guest OS
OS Family = Windows
OS Name = Windows Server 2008
All of the guest operating systems produced in that list could be protected by SRM 4.0 with one additional consideration, do you want to customize the GuestOS (for example network changes using SRM’s ip customizer tool) during recovery? If the answer to that question is NO then any of the Windows 2008 operating systems listed on the HCL page you have just generated could be protected by SRM 4.0.
If you DO wish to customize the protected guest operating system during recovery using SRM 4.0's built in image customization capability (if you know how vCenter VM image customization works then you already understand this technique) then notice in the SRM 4.0 compatibility matrix picture above there is a second paragraph that refers to guest operating system customization support.
Although the section indicates that all of the same guest operating systems can be customized there are some versions of Windows 2008 that are not currently supported by SRM 4.0 for guest customization.
Currently SRM customization support for Windows 2008 does NOT include ANY R2 versions. Windows 2008 R2 is a new release of windows and is considered by many to be the server release of Windows 7. This is really the source of the supportability differences between a Windows 2008 SP1/SP2 edition and an R2 edition.
Customization support for the R2 releases of Windows 2008 will be reviewed as part of our ongoing SRM update program.
hope this helps,