Category Archives: Microsoft

Error 25325 when creating Hyper-V cluster on VMM 2012 R2

I’m currently studying for the 70-414 exam and following the course provided by pluralsight.com. I’ve been following the videos on setting up a Hyper-V cluster using System Center Virtual Machine Manager 2012 R2.

When I got to the step of creating the cluster it was failing in my demo lab. I kept getting this error:

Error (25325) The cluster creation failed because of the following error: Network 172.16.2.0/24 has already been specified.

The 172.16.2.0 network was dedicated to the iSCSI connections. I had configured two NICs on the same subnet, connected to a VM running Windows 2012 R2 iSCSI target with MPIO. It turns out VMM does not like having multiple adapters on the same subnet. Once one of the two adapters were disabled on both hosts, the cluster creation was successful. The adapters can be enabled again after cluster creation.

Restoring SBS 2008 Backup To Hyper-V

As a test I thought I would see how the SBS 2008 backup handles restoring to a Hyper-V virtual machine. The P2V was successfull but of course there are some issues to deal with.

This is how I did it on a Windows Server 2008 R2 standard machine.

1. Attach the USB backup disk to the Hyper-V host.

2. Open Computer Management -> Disk Management and take the backup disk offline. This allows Hyper-V to attach the usb disk as an internal IDE disk.

3. Open Hyper-V manager.

4. Edit the properties of your SBS 2008 VM. Set the usb disk as the secondary device on the primary IDE channel.

5. Boot the VM using your SBS 2008 DVD or ISO.

6. Restore the system using Windows Complete PC restore.

7. When the restore is complete the VM will reboot. If everything is OK you should eventually see the login prompt.

8. You will need to rerun the connect to internet wizard to fix the network. I also noticed you’ll need to reimport your SSL certificate, so make sure you have a backup of that handy!

That was as far as I got in testing but from what I could see there shouldn’t be a major problem doing a P2V of SBS 2008 to Hyper-V.

Black Screen On SBS 2008 Startup

After having our SBS 2008 server in operation for 9 months I noticed that restarts were taking much longer than normal, around 40 minutes. On an unrelated issue I went to open Device Manager and it took some time (probably around a minute) to display the list. Viewing hidden devices (with the environment variable DEVMGR_SHOW_NONPRESENT_DEVICES enabled) is where I found the problem.

Under the section “Volume Shadow Copies” were thousands of “generic volume shadow copy” entries, most of them disabled (not present). My guess is these had been created by windows server backup and the swapping of external usb backup disks. The thousands of shadow copy devices had made the system registry hive huge, causing the delay opening device manager and the black screen at startup.

Here is my solution. Please do this at your own risk!

1. Obtain the Microsoft devcon utility from the Windows Driver Kit. This TechNet Wiki page explains how.

2. Get Rob van der Woude’s RmHidDev.bat script here.

3. Modify lines 53-56 to this:

FOR /F "tokens=1 delims=: " %%A IN ('DEVCON FindAll @STORAGE\VolumeSnapshot\HarddiskVolumeSnapshot* ^| FIND /I /V "matching device(s)"') DO (
	TYPE "%Temp%\DevconFind.txt" | FIND "%%~A" >NUL
	IF ERRORLEVEL 1 %Debug% DEVCON Remove "@%%~A"
)

4. Start an elevated command prompt.

5. Run RmHidDev.bat /Y /D >> output.txt to pipe the output to a log file. This will give a list of all devices the script will remove. Do this to double check it will only remove the disabled generic volume shadow copy devices.

6. Run RmHidDev.bat without switches to remove the devices.

After doing this Device Manager and restarts were much quicker. I noticed no issues with the backups but again do this at your own risk!

Thanks to this post as the basis of this solution.