Virtual Machine Folder ACL access denied

I upgraded a Windows 2008 Hyper-V server to R2 and one of the virtual machine failed to start with error “Account does not have sufficient priviledge to open attachment “<Virtual machine file>” (0x80070005). (Virtual machine ID <GUID>)”.

Hyper-V could not read the virtual machine files due to ACL issues. Added SYSTEM account, etc does not work as Hyper-V has it’s own Service SID “NT VIRTUAL MACHINE”

To resolve this, try the follow:

Open the directory that stores your virtual machine

Open the “Virtual Machines” subdirectory under your virtual machine directory

Record the GUID as per the file name of the .xml file in this directory

Run icacls “<virtualmachinefolder>” /grant “NT VIRTUAL MACHINE\<virtualmachineguid>”:F /T

Considerations when hosting Active Directory Domain Controllers on Virtual Machines

Just to share my experience on this topic, it mean be good to take these points into considerations when you are planning to deploy a domain controller on a Hyper-V machine.

Point number 1:

As a precaution, do not take snapshot of a Active Directory Domain Controller Virtual Machine. This is to prevent accidental or unplanned roll back of your Active Directory contents. Remember a snapshot is not a valid backup of your system state data. If you apply a snapshot of your Active Directory Domain Controller Virtual Machine, this causes an update sequence number (USN) rollback.

Point number 2:

If you take snapshot, a differencing disk AVHD file is created. And this AVHD will merge with the primary VHD file when you do a proper shutdown of the virtual machine. The duration of the merging depends on the size of the AVHD file. Now, imagine if you are unaware of this and shutdown your physical Hyper-V server machine before the merging can complete. Then you want to move, copy or migrate this domain controller virtual machine and you copy the files to a new Hyper-V server. Unknowingly, you load the unmerged VHD file on your new Hyper-V server and disaster strikes.

Point number 3:

Disable Time synchronization on your Domain Controller Virtual Server. This is to prevent time skewed. Authentication problems will occurred when your time is out of sync.

Monitoring Hyper-V Performance

For those of you who are interested in monitoring Hyper-V Performance, this article explains it!!

http://blogs.msdn.com/tvoellm/archive/2009/04/23/monitoring-hyper-v-performance.aspx

Migrate Virtual Machine from Virtual Server 2005 to Hyper-V

This post is to illustrate how to migrate a Microsoft Virtual Server 2005 R2 Virtual Machine to Windows Server 2008 Hyper-V.

My Virtual Machine is a Windows 2003 Server and I did this on a box-to-box migration. It is easy, so enjoy!



Pre migration process:

1. The guest systems needs to be upgraded to the latest Service Pack (Vista SP1, XP SP3, Windows 2003 SP2).

2. Install Windows Server 2008 onto the new machine and install Hyper-V. (make sure it you installed any hotfixes for Hyper-V too)

3. Copy the VHD to the new Hyper-V box.

4. Setup a Virtual Network on the new Hyper-V server.



Migration Steps:

1. Open Hyper-V Manager and create a new Virtual Machine.

2. Type a Name for the VM and if desired, you can store the virtual machine in a different location.

3. Specify the amount of Memory to assign to this VM.

4. Assign a Network Adapter.

5. Select "Use an existing virtual hard disk" and select the .VHD file to migrate.

6. Click Finish and start the new Virtual Machine.

7. The new VM will begin detecting and installing new hardware. If prompted to install an Unknown Device, select "Ask me again later".


*I suggest to go through the below steps although it might have to effects on some platforms

8. Uninstall the Legacy Virtual Machine Additions from Add/Remove Programs.

9. Update the HAL. Click on Start, type "msconfig", click on Boot Tab, Advanced options. Check the box "Detect Hal". Then click OK to save and OK to exit msconfig.

10. Now restart the Virtual Machine.

11. Next step is to install Microsoft Hyper-V Integration Components on the new VM. Connect to the console of the Guest system, click Action, Insert Integration Services Setup Disk. Run "Install Microsoft Hyper-V Integration Components".

12. You will get a warning that you need to upgrade the HAL. Click OK. Restart the system when installation completes.

12. You will prompted to reboot again. Reboot again and you should now boot up to your migrated Virtual Machine.