Virtualization, Cloud, Infrastructure and all that stuff in-between

My ramblings on the stuff that holds it all together

Support for Virtualized OS/Applications – an Open Debate..


Martin’s post here prompted me to blog something I’ve been meaning to do for a while.

Virtualization projects and services are cool; we all understand the advantages in power/cooling and the flexibility it can bring to our infrastructures.

But what about support, if you are a service provider (internal or outsourcing) you normally need to be able to offer an end-end SLA on your services. typically this would be backed off against a vendor like Microsoft or Oracle via one of their premium support arrangements.

From what I see in the industry, with most software vendors especially Microsoft there is almost no way a service provider can underwrite an SLA as application/OS vendors give themselves significant scope to say “unsupported configuration” if you are running it under a hypervisor or other VM technology… Microsoft use the term commercially reasonable in their official policy – who decides what this is?

I would totally accept that a vendor would not guarantee performance under a hypervisor – that’s understandable and we have tools to analyse, monitor and improve (Virtual Centre, MOM, DRS, increase resources etc.). but too many vendors seem to use it as a universal “get out of jail free card”.


Issues of applications with dependency on physical hardware aside (fax cards, realtime CPU, DSP, PCI cards etc.) In my entire career working with VM technology I’ve only ever seen one issue that could be directly attributed to being caused by virtualization – and to be fair that was really a VMTools issue; rather than VMWare itself.

Microsoft have an official list of their applications that are not supported here – why is this? speech server I could maybe understand as it would probably be timer/DSP sensitive – but the rest? Sharepoint? I know for a fact ISA does work under VMWare as I use it all the time.

Microsoft Virtual Server support policy

Support policy for Microsoft software running in non-Microsoft hardware virtualization software

Exchange is specifically excluded (depending on how you read the articles)

· On the Exchange Server 2007 System requirements page it only mentioned Unified messaging as being unsupportable in a virtual environment

· Yet on TechNet it is clear stated that “Neither Exchange 2007 nor Exchange 2007 SP1 is supported in production in a virtual environment”

Credit due to a colleague for pulling together the relevant Microsoft linkage

But I know it….

a) works fully – I do it all the time.

b) Lots of people are doing this in production with lots of users (many people at VMWorld US last year)

c) VMWare have a fully-supportable x64 hypervisor – It’s just MS that don’t

What is the industry going to do about this?, I asked this question of peers a lot at VMWorld and at BriForum; and to be honest everyone has the same concern but have a few different approaches;

Dont’ tell/ask – 99% of the time a tech support rep won’t know its running under VMWare/a.n.other hypervisor so why complicate matters by telling them – could of course back-fire on you!

Threaten – “If you won’t support under VMWare we’ll use one of your competitors applications”; however this only really works if you are the US govt. or Globocorp Inc. or operate in a very niche application market.

Mitigate – reflect this uncertainty in an SLA, best-endeavours etc. this would kill most virtualization efforts in their tracks for an enterprise customer.

The same support issue has been around for a long time; Citrix/Terminal Services, application packaging, automated installations, etc. are treated as “get out of jail free cards” by support organisations…

But whilst there are some technical constraints (usually only affecting badly written apps) with terminal services and packaging, virtualization changes the game and should make it simpler for a vendor to support as there is no complex runtime integration with a host OS + bolt-ons/hacks it’s just an emulated CPU/disk/RAM you can do whatever you like within it.

So – the open debate; what do you do? and how do you manage it?

Please comment…

4 responses to “Support for Virtualized OS/Applications – an Open Debate..

  1. vinf February 26, 2008 at 2:54 pm

    Have had some correspondence from Ben with regards to this post(aka virtual PC guy at Microsoft)… useful.

    the MS/legal angle makes things a bit clearer.. how do you handle this with your production VM platforms?



    To give you some perspective on Microsoft’s support policy of software under virtualization there are two key things that you need to understand:

    1) At Microsoft it is mostly up to the individual product teams to drive their own supports statements. This is why you see different products offering different levels of support inside of virtualization.

    2) For Microsoft to say that a product is “supported” on a virtualization platform it means that we are placing a legal liability on ourselves to be able to guarantee to customers that our software will run there and that we will correct any issues encountered on that platform. As such the “it runs okay when I try it” statement that is made in your blog is simply not sufficient. Microsoft product teams are not comfortable making statements of support unless that have conducted full, extensive testing of their product on said configurations. Given that for many product teams this can mean an investment of months of test time – they need to prioritize this work against other features that their customers are asking for.

    Please feel free to ask me for further clarification if you need it.


    Windows Virtualization Program Manager.

  2. Pingback: Virtualization Short Take #3 - - The weblog of an IT pro specializing in virtualization, storage, and servers

  3. Jay Rogers March 5, 2008 at 6:49 pm

    EVERYONE in the industry is in agreement virtualization is going to be the way of the future (and has been the way for some for many years already). Otherwise I don’t think Microsoft would be spending so much effort on Hyper-V.

    It just seems Microsoft could be fair to all those doing virtualization (especially VMware customers who have really brought this into the datacenters over the last several years and caused most of the interest in the first place).

    Could Microsoft not come up with some legal way of saying “once we suspect an issue is caused by virtualization the machine will need to be reproduced on physical for support” (there are many tools out there now to help with this)..but NOT limit the support to many of the popular Microsoft applications that are known to work in virtual fine already. (Heck, at VMworld Europe they just showed how you could exceed what normally has been possible with Exchange in a virtual environment).

    Or will Microsoft release the great Hyper-V but then say but we don’t trust you running Exchange, and this and that in hyper-v? Or will they simply suddenly find the time to test all Microsoft applications in Hyper-V (and maybe XenServer..IE Citrix due to the agreements) and certify them ok for those but not for other hypervisors?

    Microsoft has also lately warmed up to open source and I think with the virtual revolution has the chance to help us all work in the virtual world we all know is better…even if we don’t all drive the same car (ie. hypervisor).

  4. vinf June 3, 2008 at 3:42 pm

    by way of a follow-up useful article at here;

    Interesting to see the extra options for customers who OEM their vmware software with services.. they give end-end support.

    thanks to Scott

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