HYPER-V virtualization of SBS 2011 box - Please help

My friends,

I have with me a SBS 2011 server with the following config -
- Xeon x5647 CPU
- 24GB RAM
- C: = 120GB
- D: = 990GB (840GB being free) - This is only the Data drive and contains "Folder Redirections" and "Shares"(User Shares)
- F: = 3GB Recovery partition

Now, we have a requirement to run another server for an application that our company is purchasing. Because we cannot afford to buy another server, I was planning to do the following -

1. Backup the Server using Windows Image Backup (Backup Assist)
2. Install HYPER-V 2008 R2 bare metal version of operating system on it.
3. Create VHD of size 121GB and restore the Windows Image Backup onto this drive.

Now my questions are -

1. I remember reading a while ago that to restore Windows Image backup the destination disk size should be same as bigger. Could someone confirm?

2. If this is the case, I am not worried about C: drive as we have enough disk space to even take it up to 200GB. What I am concerned about is the D:\ which we wanna really compress to accomodate another server. Will we be able to go with a smaller vhd for D:\ drive for restore operation to succeed.

3. Is the Windows image backup the best option in our case to do a P2V.

4. Has anyone done a similar operation before on a SBS 2011 server who could give me some guidance. I really want this to work.

Keep in mind that it will be essentially a bare-metal restore as restoring to VHD is like restoring to a new server.

Thanks in advance.
LVL 11
Who is Participating?
Cliff GaliherCommented:
If you are going to do a bare metal recovery then yes, the destination disk must be larger tha. The original. A bare metal recovery restores all partitions (referred to as volumes in a backup/restore sense.)

I word, however, Dow critical volume backup and restore and then restore your data partition separately. This alleviates that pain point.

I have not used partition magic in years. Last I checked it did not support server OSes. As I mentioned, however, the built in server disk management console can shrink a partition just final no need for 3rd party.

RecoverAssist isn't about injecting drivers. It is a tool that, among other things, strips drivers out. When you first install Windows (server or client) you'll notice one of the steps is "detecting your hardware." that will scan all of your hardware, set a HAL type, and set up those drivers in the registry. Backups will include all of that information.

In some cases, if you restore to different hardware, because the drivers are still present, they try to load and co flit with the new hardware...and bam..blue screen. The good HIR products will, as they restore the data, pull out the driver references from the registry so they don't load and cause the blue screen. The HIR product will also flip the detection routine back on so it runs just as of it were a new install (much like sysprep does for OEM and corporate image biulders) so that new hardware is properly detected and new drivers referenced.

Even in a P2V restore, the virtual hardware can cause conflicts. An HIR product should be used to restore whenever possible,
Cliff GaliherCommented:
Yes, the partition being restored to must be the same size or larger.

As long as you have the free space and there isn't heavy fragmentation, you can shrink your D: partition so you can have a smaller image and restore point. Make a backup BEFORE shrinking as well, however, in case the shrink operation causes issues. Disk manager in windows can shrink the partition. He 3rd party tools required.

If you have an up-to-date backupassist license, you also have access to a companion tool called recoverassist. It can restore a backupassist backup in a hardware independent fashion so you get the net effect of a P2V. That is you beat option given the information you've provided.

I have indeed done this type of migration several times. The guidance above should get you through safely with proper planning and testing. As for testing, no reason you can't install hyper-v on an unused workstation, disconnected from your production network, and do test restores to identify problems.
manav08Author Commented:
Hi cgalier,

So does the D:\ partition must also be of same size when doing restore operation??
I thought it only applies to system drive?

Secondly, after what you posted above, I sent an email to Backup Assist and this is their response, so I am confused :~, if at all it is possible. Shrink may not be a soln in our case.

1. Windows Server Backup (which is the back end of the Windows Imaging engine in BackupAssist) does require the physical disk you're restoring to be of equal or larger size than the physical disk that the backup was originally taken from.

2. Unfortunately since the values determined by the backup are based on the size of the physical disk, you will require the same sized disk (or larger) to restore to. I don't believe that compression will be taken into account for this.
3. & 4. The Windows Imaging option is easily the most recommended method of performing a P2V migration, however if what has been mentioned above is a large issue then you can perform a file based backup using the File Replication or Zip engines. The only difference is that you'll need to install Windows first, then perform the restore of your data on the clean install. With the imaging engine you'll be able to restore the data and install the operating system in one step.

More information about the Zip and File Replication engines can be found by visiting:
As you mentioned, if you do perform an imaging backup it's essentially a bare metal recovery (most likely to dissimilar hardware). If you do perform a restore in this way, then I suggest that you take a look at RecoverAssist as this can help avoid blue screen issues which may arise from restoring to dissimilar hardware. This tool comes free with BackupAssist v6.4.0 and later: http://www.backupassist.com/BackupAssist/tour_RecoverAssist.html
Improve Your Query Performance Tuning

In this FREE six-day email course, you'll learn from Janis Griffin, Database Performance Evangelist. She'll teach 12 steps that you can use to optimize your queries as much as possible and see measurable results in your work. Get started today!

Lee W, MVPTechnology and Business Process AdvisorCommented:
If I remember correctly, use a dynamic VHD and the data VHD can be larger than the actual drive size, the used space is what will really matter.
Cliff GaliherCommented:
Unfortunately, by default the windows backup utility (and the default engine that drives backupassist) is image based. This is fundamentally different than file-based backups, and thus the destination drive MUST be as large as the source due to how images store block-level data. Yes, this includes non-system drives.

While you posted backupassist's reply, you did not explain the soirce of your confusion. As far as I can tell, their advice aligns with my own. As I said, if you have a current license agreement for backupassist, you have access to recoverassist, and it'll help with hardware independent restores where the native restore will likely blue-screen (RAID drivers being the common culprit.)
manav08Author Commented:

you could be right but dynamic VHD ahs some performance implications in HYPER-V. I have never user dynamic VHD, I always convert them to Fixed.
manav08Author Commented:

The confusion is that BA are saying that I have to use bigger or same size disks even for data drive and it doesn't matter even if I shrink the partition size, because it works on the underlying physical drive rather than partition.

Whereas you advise was to shrink the D:\ drive and then do a backup and restore will work fine. This is what has created confusion.

I have used a tool called Easeus partition magic in the past. Will that work in this case?

Re: Recover Assist - I believe it is a tool like Acronis Univeral restore which helps in injecting drivers. As far as I understand we won't need to inject any drivers? if we do, what will these be?
As far as I understand, prior to introduction of this recoverassist module, the bare metal restores of Windows Image backup should just work. am I not right in saying that?
manav08Author Commented:
Leew has created another confusion now regarding dynamic discs :). Why can't life just be easy
manav08Author Commented:
Thanks for clarification on RecoverAssist. It sounds very similar to universal restore by Acronis

Now back to original question -

You are saying that

1.  I shrink the D:\ drive to lets say 661Gb which is the minimum windows will allow (I just checked).
2. I backup the Server using BA.
3. I use Recover Assist to first restore the C:\ (OS) and then do the restore of D:\ drive.

Now questions are -

1. I still don't understand how doing the 2 separately will help in our case

2. I have noticed that the D:\ drive is also the storage point for SQL program files for Share Point so I am worried about breaking something if we do the 2 separately.

3. I have used EASEUS Magic on a windows 2008 server before. It is just a partitioning tool, like Partition Magic from back in the days.

4. I must use the above software or else shrink doesn't give me enough storage space.

5. This brings me to the conflict point again which is what backup assist team raised and what they are saying is that it will not work. Quoted - "2. Unfortunately since the values determined by the backup are based on the size of the physical disk, you will require the same sized disk (or larger) to restore to. I don't believe that compression will be taken into account for this."
Cliff GaliherCommented:
Backupassist uses the WSB as an engine. Different backup options have different restore requirements. Volume level backups only require the volumes be the same size or larger. Bare-,etal backups require the full disk be larger.  It all depends in your backup strategy. Perhaps you should study the basics of WSB before proceeding, or use a different product that supports HIR, such as Acronks r StorageCraft. Otherwise this response would take an hour to read and be worthy if publication.

More info on WSB and its supported options:


manav08Author Commented:

I think we are having difficulty explaining each other.

All I wanna know is that if I shrink D:\ drive using partitioning tool will backup assist restore to a smaller VHD work?
Cliff GaliherCommented:
If you back up by volume, yes. If you back up by bare metal, no.
manav08Author Commented:
So when I backup using backup assist, I select the volumes independently?
When I open up BA and go to Volume Selection, I have 3 tabs

1. Recovery type - System Volumes (BAreMetalRecovery) or Data Files
2. Volumes - Here I can chose the volumes
3. Applications.

Are you saying that I do a backup of System Volumes (exclude d:\) and then do an independent volume backup of just the D:\ drive (by selecting DATA Files option in Tab 1)

And when I do a bare metal restore I use backup 1 for that and backup 2 for the D:\ drive. Will this not break anything considering I have sharepoint in D:\ drive?
Cliff GaliherCommented:
I'd test it with a test machine as I out,oned earlier, but yes that is the general theory. And as long as you properly restore the volumes, nothing should break.
manav08Author Commented:
Hi Guys, I never actually proceeded with this but awarding points on the basis of the solution that I was most likely to use. Thanks for your help
Question has a verified solution.

Are you are experiencing a similar issue? Get a personalized answer when you ask a related question.

Have a better answer? Share it in a comment.

All Courses

From novice to tech pro — start learning today.