Tag Archives: hyper-v

Microsoft takes aim at VMware, talks cloud and mobile device management at MMS 2013

I am attending the Microsoft Management Summit in Las Vegas (between 5 and 6,000 attendees I was told), where Brad Anderson, corporate vice president of Windows Server & System Center, gave the opening keynote this morning.


There was not a lot of news as such, but a few things struck me as notable.

Virtualisation rival VMware was never mentioned by name, but frequently referenced by Anderson as “the other guys”. Several case studies from companies that had switched from “the other guys” were mentioned, with improved density and lower costs claimed as you would expect. The most colourful story concerned Dominos (pizza delivery) which apparently manages 15,000 servers across 5,000 stores using System Center and has switched to Hyper-V in 750 of them. The results:

  • 28% faster hard drive writes
  • 36% faster memory speeds
  • 99% reduction in virtualisation helpdesk calls

That last figure is astonishing but needs more context before you can take it seriously. Nevertheless, there is momentum behind Hyper-V. Microsoft says it is now optimising products like Exchange and SQL Server specifically for running on virtual machines (that is, Hyper-V) and it now looks like a safe choice, as well as being conveniently built into Windows Server 2012.

I also noticed how Microsoft is now letting drop some statistics about use of its cloud offerings, Azure and Office 365. The first few years of Azure were notable in that the company never talked about the numbers, which is reason to suppose that they were poor. Today we were told that Azure storage is doubling in capacity every six to nine months, that 420,000 domains are now managed in Azure Active Directory (also used by Office 365), and that Office 365 is now used in some measure by over 20% of enterprises worldwide. Nothing dramatic, but this is evidence of growth.

Back in October 2012 Microsoft acquired a company called StorSimple which specialises in integrating cloud and on-premise storage. There are backup and archiving services as you would expect, but the most innovative piece is called Cloud Integrated Storage (CiS) and lets you access storage via the standard iSCSI protocol that is partly on-premise and partly in the cloud. There was a short StorSimple demo this morning which showed how how you could use CiS for a standard Windows disk volume. Despite the inherent latency of cloud storage performance can be good thanks to data tiering, which puts the most active data on the fastest storage, and the least active data in the cloud. From the white paper (find it here):

CiS systems use three different types of storage: performance-oriented flash SSDs, capacity- oriented SAS disk drives and cloud storage. Data is moved from one type of storage to another according to its relative activity level and customer-chosen policies. Data that becomes more active is moved to a faster type of storage and data that becomes less active is moved to a higher capacity type of storage. 

CiS also uses compression and de-duplication for maximum efficiency.

This is a powerful concept and could be just the thing for admins coping with increased demands for storage. I can also foresee this technology becoming part of Windows server, integrated into Storage Spaces for example.

A third topic in the keynote was mobile device management. When Microsoft released service pack 1 of Configuration Manager (part of System Center) it added the ability to integrate with InTune for cloud management of mobile devices, provided that the devices are iOS, Android, Windows RT, or Windows Phone 8. A later conversation with product manager Andrew Conway confirmed that InTune rather than EAS (Exchange ActiveSync) policies is Microsoft’s strategic direction for mobile device management, though EAS is still used for Android. “Modern devices should be managed from the cloud” was the line from the keynote. InTune includes policy management as well as a company portal where users can install corporate apps.

What if you have a BlackBerry 10 device? Back to EAS. A Windows Mobile 6.x device? System Center Configuration Manager can manage those. There is still some inconsistency then, but with iOS and Android covered InTune does support a large part of what is needed.

Microsoft’s growth areas: Azure, Server with Hyper-V, Office 365, Windows Phone

Microsoft has left slip a few figures in posts from PR VP Frank Shaw and platform evangelist Steve Guggenheimer.

Observers have tended to focus on Windows “Blue” and what is happening with Microsoft’s core client operating system, but what caught my eye was a few figures on progress in other areas.

  • Windows Azure compute usage doubled in six months
  • Windows Azure revenue growing 3X
  • Office 365 paid seats tripled year on year last quarter
  • Server 2012 Datacenter edition licenses grown 80%

A notable feature of these figures is that they are relative, not absolute. Office 365 is a relatively new product, and Windows Azure (from what I can tell, since Microsoft did not release numbers) performed rather badly until its renaissance in early 2011 under Satya Nadella, Scott Guthrie and others – see here for more about this). It is easy to post big multiples if you are starting from a small base.

This is real progress though and my guess is that growth will continue to be strong. I base this not on Microsoft’s PR statements, but on my opinion of Office 365 and Windows Azure, both of which make a lot of sense for Microsoft-platforms organisations migrating to the cloud.

Why the growth in Server 2012 Datacenter? This one is easy. Datacenter comes with unlimited licenses for Windows Server running in Hyper-V virtual machines on that server, so it is the best value if you want to the freedom to run a lot of VMs, especially if some of those VMs are lightly used and you can afford to overcommit the processors (you need a new license for every two physical processors you install).

Here’s another figure that Shaw puts out:

Windows Phone has reached 10 percent market share in a number of countries, and according to IDC’s latest report, has shipped more than Blackberry in 26 markets and more than iPhone in seven.

Spin, of course. This February report from IDC gives Windows Phone just a 2.6% market share in the 4th quarter of 2012. Still, it did grow by 150% year on year, thanks no doubt to Nokia’s entry into the market.

My personal view is that Windows Phone will also continue to grow. I base this on several things:

  • I see more Windows Phones on the high street and in people’s hands, than was the case a year ago.
  • Windows Phone 8 is decent and the user interface is more logical and coherent than Android, which mitigates a lack of apps.
  • Nokia is bringing down the price for Windows Phone devices so they compare well with Android in the mid-market below Apple and the premium Android devices.
  • There is some momentum in Windows Phone apps, more so than for Windows 8. Guggenheimer notes that downloads from the Phone Store now exceed 1 billion.

The context of the above is not so good for Microsoft. It is coming from behind in both cloud and mobile and the interesting question would what kind of market share it is likely to have in a few years time: bigger than today, perhaps, but still small relative to Amazon in cloud and Apple and Android in mobile.

There is also the Windows 8 problem. Many prefer Windows 7, and those who use Windows 8, use it like Windows 7, mostly ignoring the tablet features and new Windows Runtime personality.

How will Microsoft fix that? Along with leaked builds of Windows Blue, Microsoft has announced the next Build conference, which will be in San Francisco June 26-28, 2013 (I am glad this will not be on the Microsoft campus again, since this venue has not worked well). There is a lot to do.


Microsoft’s Hyper-V Server 2012: too painful to use?

A user over on the technet forums says that the free standalone Hyper-V is too painful to use:

I was excited about the free stand-alone version and decided to try it out.  I downloaded the Hyper-V 2012 RC standalone version and installed it.  This thing is a trainwreck!  There is not a chance in hell that anyone will ever use this thing in scenarios like mine.  It obviously intended to be used by IT Geniuses in a domain only.  I would really like a version that I can up and running in less than half an hour like esxi.  How the heck is anyone going to evaluate it this in a reasonable manner? 

To be clear, this is about the free Hyper-V Server, which is essentially Server Core with only the Hyper-V role available. It is not about Hyper-V in general as a feature of Windows Server and Windows 8.

Personally I think the standalone Hyper-V Server is a fantastic offering; but at the same time I see this user’s point. If you join the Hyper-V server to a Windows domain and use the administration tools in Windows 8 everything is fine; but if you are, say, a Mac user and download Hyper-V Server to have a look, it is not obvious what to do next. As it turns out you can get started just by typing powershell at a command prompt and then New-VM, but how would you know that? Further, if Hyper-V is not joined to a domain you will have permission issues trying to manage it remotely.

Install Hyper-V Server, and the screen you see after logging on does not even mention virtualization.


By contrast, with VMWare’s free ESXi has a web UI that works from any machine on the network and lets you get started creating and managing VMs. It is less capable than Hyper-V Server; but for getting up and running quickly in a non-domain environment it wins easily.

I have been working with Hyper-V Server 2012 myself recently, upgrading two servers on my own network which run a bunch of servers for development and test. From my perspective the free Hyper-V Server, which is essentially Server Core with only the Hyper-V role available, is a great offer from Microsoft, though I am still scratching my head over how to interpret the information (or lack of it) on the new product page, which refers to the download as a trial. I am pretty sure it is still offered on similar terms to those outlined for Hyper-V Server 2008 R2 by Program Manager Jeff Woolsey, who is clear that it is a free offering:

  • Up to 8 processors
  • Up to 64 logical processors
  • Up to 1TB RAM
  • Up to 64GB RAM per VM

These specifications may have been improved for Hyper-V Server 2012; or perhaps reduced; or perhaps Microsoft really is making it a trial. It is all rather unclear, though I would guess we will get more details soon.

It is worth noting that if you do have a Windows domain and a Windows 8 client, Hyper-V Server is delightfully easy to use, especially with the newly released Remote Server Administration Tools that now work fine with Windows 8 RTM, even though at the time of writing the download page still says Release Preview. You can use Server Manager as well as Hyper-V Manager, giving immediate access to events, services and performance data, plus a bunch of useful features on a right-click menu:


In addition, File and Storage services are installed by default, which I presume means you can use Storage Spaces with Hyper-V Server, which could be handy for hosting VMs with dynamically expanding virtual hard drives. Technically you could also use it as a file server, but I presume that would breach the license.

For working with VMs themselves of course you have the Hyper-V Manager which is a great tool and not difficult to use.


The question then: with all the work that has gone into these nice GUI tools, why does Microsoft throw out Hyper-V Server with so little help that a potential customer calls it “too painful to use”?

Normally the idea of free editions is to entice customers into upgrading to a paid-for version. That is certainly VMWare’s strategy, but Hyper-V seems to be different. It is actually good enough on its own that for many users it will be a long time before there is any need to upgrade. Microsoft’s hope, presumably, is that you will run Windows Server instances in those Hyper-V VMs, and these of course do need licenses. If you buy Windows 8 to run the GUI tools, that is another sale for Microsoft. In fact, the paid-for Windows Server 2012 can easily work out cheaper than the free editions, if you need a lot of server licenses, since they come with an allowance of licenses for virtual instances of Windows Server. Hyper-V Server is only really free if you run free software, such as Linux, in the VMs.

Personally I like Hyper-V Server for another reason. Its restricted features mean that there is no temptation to run other stuff on the host, and that in itself is an advantage.

Upgrading to Hyper-V Server 2012

After discovering that in-place upgrade of Windows Hyper-V Server 2008 R2 to the 2012 version is not possible, I set about the tedious task of exporting all the VMs from a Hyper-V Server box, installing Hyper-V Server 2012, and re-importing.

There are many reasons to upgrade, not least the irritation of being unable to manage the VMs from Windows 8. Hyper-V Manager in Windows 8 only works with Windows 8/Server 2012 VMs. It does seem to work the other way round: Hyper-V Manager in Windows 7 recognises the Server 2012 VMs successfully, though of course new features are not exposed.

The export and import has worked smoothly. A couple of observations:

1. Before exporting, it pays to set the MAC address of virtual network cards to static:


The advantage is that the operating system will recognise it as the same NIC after the import.

2. Remove any snapshots before the export. In one case I had a machine with a snapshot and the import required me to delete the saved state.

3. After installing Hyper-V 2012, don’t forget to check the date, time and time zone and adjust if necessary. You can do this from the sconfig menu.

4. The import dialog has a new option, called Restore:


What is the difference between Register and Restore? Do not bother pressing F1, it will not tell you. Instead, check Ben Armstrong’s post here. If you choose Register, the VM will be activated where it is; not what you want if you mistakenly ran Import against a VM exported to a portable drive, for example. Restore on the other hand presents options in a further step for you to move the files to another location.

5. For some reason I got a remote procedure call failed message in Hyper-V Manager after importing a Linux VM, but then when I refreshed the console found that the import had succeeded.

6. Don’t forget to upgrade the integration services. Connect to the server using the Hyper-V Manager, then choose Insert Integration Services Setup Disk from the Action menu.


Cosmetically the new Hyper-V Server looks almost identical to the old: you log in and see two command prompts, one empty and one running the SConfig administration menu.

Check the Hyper-V settings though and you see all the new settings, such as Enable Replication, Virtual SAN Manager, single-root IO virtualization (SR-IOV), extension support in a virtual switch, Live Migrations and Storage Migrations, and more.

No in-place upgrade for Hyper-V Server 2012

Microsoft’s free Hyper-V Server is a great bargain though I am beginning to think the company is pulling back on the idea. It is there for download; but the home page makes no mention of the fact that it is free, and the download page calls it trial software:


Further, support information for this specific edition is hard to come by. Here is one thing I discovered though: there is no in-place upgrade from Hyper-V Server 2008 R2, though the setup teases. This is what you get. First, an offer to upgrade in-place:


with the text, “This option is only available when a supported version of Hyper-V Server is already running on this computer”.

and then the bad news:


which in case you cannot read it says,  “Hyper-V Server (Server Core) cannot be upgraded to Hyper-V Server 2012”.

This document, which covers in-place upgrade options for Server 2012, does not even mention Hyper-V Server. It does say this about Server Core, on which Hyper-V Server is based:

Upgrades that switch from a Server Core installation to the Server with a GUI mode of Windows Server 2012 in one step (and vice versa) are not supported. However, after upgrade is complete, Windows Server 2012 allows you to switch freely between Server Core and Server with a GUI modes.

Note that it says “in one step”, suggesting that an upgrade from Server Core to Sever Core should work; then you can add the GUI later if you want. In the case of Hyper-V Server, there is no GUI option anyway; so you would have thought it should be OK. Given the lack of attention to this edition generally though, I wonder if it is a victim of “it’s the free version, let’s not bother".

Incidentally, in-place upgrade from Hyper-V Server 2008 to Hyper-V Server 2008 R2 worked fine.

Ubuntu 12.04: a fresh take on Linux

Canonical has released Ubuntu 12.04, a “long term support” version which will be supported for five years on both desktop and server.

I installed the new release on Microsoft’s Hyper-V. Installation was straightforward: download iso of install CD, mount in new Hyper-V VM, install, and wait while updates are downloaded.

This is the first time I have tried Unity, the desktop shell originally designed for netbooks which is now the default in Ubuntu. It is a clean, minimalist shell with a launcher on the left edge. The launcher is like the Windows 7 taskbar, in that it lets you quit as well as launch applications. The screenshot below is more or less the default, though I have added Google Chrome and locked the Terminal to the launcher.


I found the new Ubuntu a little perplexing at first. What about applications not on the launcher?

The secret is the top left button, called Dash home. Click this, and a dashboard appears.


At the foot of the screen are icons for Home, Applications, Files and folders, Music and video. Each one displays different shortcuts, but also operates as a search scope. In Ubuntu 12.04 search is a primary means of navigation. For example, to install the Audacity sound editor, I selected Applications and typed “Aud”. Audacity was then listed as an app available for download. There is also the Ubuntu Software Centre which is Ubuntu App Store.


Where the search UI gets rather odd is with the new Head Up Display (HUD). Run Audacity and it appears without any menu. If you click on the top bar (Mac style) the menu bar appears. Alternatively, you can press Alt, and a search box appears that says “Type your command”. I typed “pref” and the Preferences menu items appeared in a list.


However, this only works for applications that support it. If you run a LibreOffice app (the office suite that comes with Ubuntu 12.04) and press Alt, you get the HUD search but it will apply to the Ubuntu desktop and not the Libre Office app.

Some apps, such as Terminal, show menus both on the app window and in the top bar. All a bit messy and confusing.

Underneath it is still a variant of Debian Linux of course.

The strong points of Linux, and Ubuntu in particular, are evident in this release as you would expect, including multiple desktop workspaces, and easy discovery and install of new applications. Another key feature is Ubuntu One, cloud storage and sync with 5GB free. An additional 20GB is $29.99 a year. There is also a music streaming service for $39.99 a year, with 20GB of storage included and apps for iOS and Android. This only covers streaming of your own music files and photos, though you can purchase additional tracks from the Ubuntu One Music Store.

I have long since given up expecting that Ubuntu, or any desktop Linux, will truly unsettle Windows or Mac, even though considering the price (free), Ubuntu 12.04 is great, and with applications like LibreOffice, Thunderbird, Firefox and Chrome, and GIMP, it easily meets everyday computing needs. Rather, it is Android, which is Linux-based, that has disrupted mobile computing, and in tablet form is beginning to encroach on laptop territory. Still, I doubt Android would have happened without desktop Linux before it.

Microsoft Hyper-V Annoyance: special permissions for VHDs

Today I needed to enlarge a virtual hard drive used by a Hyper-V virtual machine.

No problem: I used the third-party VHD Resizer which successfully copied my existing VHD to a new and larger one.

The snag: when I renamed the VHDs so that the new one took the place of the old, the VM would not start and Hyper-V reported “Access Denied”.

I looked at the permissions for the old VHD and noticed that they include full access for an account identified only by a GUID. Even more annoying, you cannot easily add those permissions to another file, as the security GUI reports the account as not found.

The solution comes from John Dombrowski in this thread:

1. Shutdown the VM
2. Detach the VHD file, apply changes
3. Reattach the VHD file, apply changes

This replaced the correct GUID for the VM.

Incidentally, this might not work if you use a remote Hyper-V manager. Permissions for remote management of Hyper-V are a notoriously prickly thing to set up. I have had problems on occasion with importing VMs, where this did not work from the remote management tool but did work if done on the machine itself, with similar access denied errors reported. If you use exactly the same account it should not be a problem, but if the remote user is different then bear this in mind.

Migrating from physical to virtual with Hyper-V and disk2vhd

I have a PC on which I did most of my work for several years. It runs Windows XP, and although I copied any critical data off it long ago, I still wheel it out from time to time because it has Visual Studio 6 and Delphi 7 projects with various add-ins installed, and it is easier to use the existing PC than to replicate the environment in a virtual machine.

These old machines are a nuisance though; so I thought I’d try migrating it to a virtual machine. There are numerous options for this, but I picked Microsoft Hyper-V because I already run several test servers on this platform with success. Having a VM on a server rather than on the desktop with Virtual PC, Virtual Box or similar means it is always easily available and can be backed up centrally.

The operation began smoothly. I installed the free Sysinternals utility Disk2vhd, which uses shadow copy so that it can create a VHD (virtual hard drive) from the system on which it is running. Next, I moved the VHD to the Hyper-V server and created a new virtual machine set to boot from that drive.

Windows XP started up first time without any blue screen problems, though it did ask to be reactivated.


I could not activate yet though, because XP could not find a driver for the network card. The solution was to install the Hyper-V integration services, and here things started to go wrong. Integration services asked to upgrade the HAL (Hardware Abstraction Layer), a key system DLL:


However, on restart I got the very same dialog.

Fortunately I was not the first to have this problem. I was prepared for some hassle and had my XP with SP3 CD ready, so I copied and expanded halaacpi.dll from this CD to my system32 folder and amended boot.ini as suggested:

multi(0)disk(0)rdisk(0)partition(2)\WINDOWS=”Disk2vhd Microsoft Windows XP Professional” /FASTDETECT /NOEXECUTE=OPTIN /HAL=halaacpi.dll

I rebooted and now the integration services installed OK. However, if you do this then I suggest your delete the /HAL=halaacpi.dll argument before rebooting again, as with this in place Windows would not start for me.  In fact, you can delete the special Disk2vhd option in boot.ini completely; it is no longer needed.

After that everything was fine – integration worked, the network came to life and I activated Windows – but performance was poor. To be fair, it was not that good in hardware either. Still, I am working on it. I’ve given the Virtual Machine 1.5GB RAM and dual processors. Removing software made obsolete by the migration, things like the SoundMAX and NVIDIA drivers seemed to help quite a bit. It is usable, and will improve as I fine-tune the setup.

Overall, the process was easier than I expected and getting at my old developer setup is now much more convenient.

Using backup on Windows Hyper-V Server or Server Core

Hyper-V Server 2008 R2 is a free virtualisation platform from Microsoft and an excellent bargain; I guess it is something Microsoft feels it has to do in order to compete with VMWare’s vSphere Hypervisor (ESXi) which is also free. Of course Microsoft still gets your money if you run Windows Server on the VMs, in either case. Hyper-V Server is in essence Windows Server Core with just the Hyper-V Role enabled, which means there is no full GUI, just a command window and a few odd GUI apps like Task Manager, Notepad and Registry Editor which Microsoft decided we cannot live without.

So what happens if you want to backup Hyper-V Server with built-in tools? Windows Server Backup is not available, first because it is a GUI application, and second because it is not installed.

There is a way. Windows Server Backup has a command-line version called Wbadmin. In some ways it is better, because you can script it, schedule it, and easily configure it through command-line arguments. It is not installed by default on Hyper-V Server or Server Core, but you can add it:

ocsetup WindowsServerBackup

Aside: If you want to see what else you can install with ocsetup, try oclist. You can install all sorts of things on Hyper-V Server, using this and third-party software, but note the terms of the EULA:

2(b). The instance of the server software running in the physical operating system environment may be used only to:
· provide hardware virtualization services, and/or
· run software to manage and service operating system environments on the licensed server.

Backup comes into that category in my opinion, but there could be areas of uncertainty. Using Hyper-V Server as a general-purpose file server would be a breach of the license, but using a file share on Hyper-V Server to copy some utilities which which to manage the server should be OK. I think – consult your lawyer.

Once you have Wbadmin installed you can backup the server. Attach an external hard drive, say to drive E, and run:

wbadmin start backup -backupTarget:e: -include:c:,d: -quiet

Actually that is not quite right, though it was my first effort. If you run this, even on a system with only C and D drives, you will get a warning:

Note: The list of volumes included for backup does not include all the volumes that contain operating system components. This backup cannot be used to perform a system recovery. However, you can recover other items if the destination media type supports it.

The reason for this is that current versions of Windows use a hidden system partition by default. This partition does not have a drive letter, but is needed for system recovery. In order to include it, add the –allCritical argument:

wbadmin start backup -backupTarget:e: -include:c:,d -quiet -allCritical

This will add the hidden partition to the backup, and enable system recovery, where you can restore the OS and all its data in once operation.

Another important argument is –vssFull. This switch in effect tells the operating system it has been backed up. The archive bit on changed files is flipped. You want this to happen if this is your only backup, but you don’t want this to happen if you are also using another type of backup.

Note that you can quit the backup with Ctrl-C but in fact it continues running. If you quit and then want to check the status, type:

wbadmin get status

and if you really want to quit:

wbadmin stop job

Backing up running VMs

Now the interesting bit. Can we backup VMs while they are running?

It should be possible, though Microsoft does not make it easy. The idea is that the backup saves the state of the VM in a snapshot, and backs up the snapshot. This means it should start cleanly on restore. But there are several tricky points.

First, if you want to backup VMs from the host, you need to set a registry key – see the following article. I would like to know why this is not set by default – it must be deliberate, since the requirement has stayed the same in Server 2008 and Server 2008 R2.

Second, there are actually two different snapshot mechanisms, one operating entirely on the host called “saved state”, and one operating in conjunction with integration services in the VM, called “Child VM snapshot”, according to the most detailed official article on the subject. This feature is shown in Hyper-V settings as Backup integration. For the Child VM Snapshot to work, there is a further limitation, that:

The Snapshot File Location for the VM is set to be the same volume in the host operating system as the VHD files for the VM.

I am not sure what happens if you have VHDs in several locations, as you might do if you wanted to optimize performance by having VHDs on different physical disks. [Update – apparently in Windows Server 2002 R2 the .AVHD snapshot files are always in the same location as their parent VHD, and this is on a per-VHD basis, so it should not be a problem in R2].

Third, there is a question mark about whether either method works for VMs running Active Directory:

Active Directory does not support any method that restores a snapshot of the operating system or the volume the operating system resides on. This kind of method causes an update sequence number (USN) rollback. When a USN rollback occurs, the replication partners of the incorrectly restored domain controller may have inconsistent objects in their Active Directory databases. In this situation, you cannot make these objects consistent.

I am also not clear whether archive bits are flipped in the child VM, if you use –vssfull along with the Child VM snapshot. If so, you should definitely not use –vssFull in the host if you are also backing up from the guest. I am trying to get clarification on these points.

These are more questions than I would like for something as critical as backup and restore of VMs. For peace of mind you should either shut them down first, which is unacceptable in most production environments, or else backup from the guest instead of, or in addition to, backing them up from the host. I’ll update this post when I get further information.

Data Protection Manager

Finally, note that in grown-up Microsoft environments you are meant to use Data Protection Manager (DPM) rather than fiddling around with wbadmin. There is even a white paper on how this integrates with Hyper-V. Ultimately though this is also based on VSS so some of the same issues may apply. However, if you are using the free Hyper-V Server 2008 R2, you are probably not in the market for DPM and its additional hardware, software and licensing requirements.

Bare-metal recovery of a Hyper-V virtual machine

Over the weekend I ran some test restores of Microsoft Hyper-V virtual machines. You can restore a Hyper-V host, complete with its VMs, using the same technique as with any Windows server; but my main focus was on a different scenario. Let’s say you have a Server 2008 VM that has been backed up from the guest using Windows Server Backup. In my case, the backup had been made to a VHD mounted for that purpose. Now the server has been stolen and all you have is your backup. How do you restore the VM?

In principle you can do a bare-metal restore in the same way as with a physical machine. Configure the VM as closely as possible to how it was before, attach the backup, boot the VM from the Server 2008 install media, and perform a system recovery.

Unfortunately this doesn’t work if your VM uses VHDs attached to the virtual SCSI controller. The reason is that the recovery console cannot see the SCSI-attached drives. This is possibly related to the Hyper-V limitation that you cannot boot from a virtual SCSI drive.

The workaround I found was first to attach the backup VHD to the virtual IDE controller (not SCSI), so the recovery console can see it. Then to do a system recovery of the IDE drives, which will include the C drive. Then to shutdown the VM (before the restart), mount both the backup and the SCSI-attached VHDs on the host using diskpart, and use wbadmin to restore each individual volume. Finally, detach the VHDs and restart the VM.

It worked. One issue I noticed though is that the network adapter in the restored VM was considered different to the one in the original VM, even though I applied the same MAC address. Not a great inconvenience, but it meant fixing networking as the old settings were attached to the NIC that was now missing.

I’ve appended the details to my post on How to backup Small Business Server 2008 on Hyper-V.