Today Microsoft finally released the System Center Virtual Machine Manager Self Service Portal 2.0 (SCVMMSSP2), and after glancing over the documentation, [when it comes to scripting LUN creation] it looks to me like 2008 all over again. Evidently, the Self Service Portal team didn’t get the memo about how nobody liked “one VM per LUN” — a major flaw in the initial version of Hyper-V, for which Cluster Shared Volumes (CSVs) were the cure.
Just take a look at this excerpt from the “Extensibility Guide”:
Although the Cluster Shared Volumes feature of Windows Server 2008 R2 allows you to store more than one virtual machine on a single LUN and retain the ability to migrate individual virtual machines between hosts, the self-service portal requires a one-to-one ratio between LUNs and virtual machines.
Curiously, in a press release today, Microsoft claims that SCVMMSSP2 “…makes it easier for customers to pool, allocate, consume and manage their computer, network and storage resources — critical components for a private cloud platform.”
How will one VM per LUN make storage management easier for you?
[UPDATE: I’m told that SCVMMSSP2 works just fine with CSVs — the documentation is not to be interpreted literally, as it only applies to scripting new LUNs.]
Eric, thanks for going through our documents for the Self Service Portal 2.0. I would like to clarify that the section which you are referring to is talking about how to extend the action of creating a LUN. We will clean up the docs to make that distinction, but referring to that text and indicating that the SSP 2.0 is not compatible or does not support using CSV is incorrect. This section is about creating LUN’s for VM’s. CSV operates at a higher abstraction than this.
Regards
Vijay
(Vijay Tewari)
Microsoft Corporation.
Vijay,
Thanks for pointing out my erroneous interpretation of the SCVMMSSP2 documentation. I’ve updated this article to clarify that one VM per LUN is only a requirement when scripting.
Eric
Actually the GUI allows for SCVMM2012 to do hardware based SnapShot VM Creation. That is where the 1 VM per LUN restriction comes from. It relys on SMI-S which as a standard lets you control array LUN operations. If you are willing to open a Powershell prompt and kick off a powershell script, you can still support a CSV with Many VMs per LUN. This would be accomplished via Sub-LUN Clones, which is still not supported by SMI-S standard.
So to sum up…
Using the SCVMM 2012 GUI I can create hardware LUN snapshots and create instant VMs.
or
I can kick off my own PowerShell scripts that allow for SUB-LUN clones to support CSVs.
or
I can use SCVMM to copy my VM into place over ethernet in which case CSVs can still be supported but no longer instant.
I like VMware FUD 😉