Month: January 2009

Hyper-V uses a whole series of files for a VM.  Here’s some of them:

• The VHD or virtual hard disk where your VM’s operating system, applications and data are stored.
• An XML file for the VM configuration.
• Snapshot files, including an XML file
• A symbolic link (shortcut with permissions) to the virtual machine configuration file.
• A symbolic link (shortcut with permissions) to the snapshots.

There is a disaster scenario where you lose your VM configuration and need to add in a new one.  For example, I had an issue several months ago where antivirus locked my VM configuration files.  No matter what I did (remove AV and reboot) Hyper-V no longer tried to load nor could even see the affected VM’s after that.  PSS tried to recreate the symbolic links but this failed to sort out my issue.

The Virtual PC Guy recently blogged about a post by Robert Vierthaler where he described how to do this.  I must mention that this is NOT SUPPORTED BY PSS.  They see it as the first part of recovering the VM.  After that, they say you need to do a full backup of the VM and rebuild/recover the backup.  Yes I know; that’s not very satisfactory but it’s better than nothing.

Credit: Virtual PC Guy.

The annual conference run by Mark Minasi is on again this year, this time in April in Virginia Beach, USA.  The agenda as of now (subject to change) is:

Sunday, April 19, 2009

• 1:00 pm:  Welcome
• 1:15 pm:   TBD  Keynote  by Windows IT Pro
• 2:30 pm:  Break
• 2:45 pm:  Mark Minasi   Introducing Windows 7
• 4:00 pm:  Break
• 4:15 pm:  Aiden Finn   Hyper-V – The Future of Infrastructure
• 5:30 pm:  Close

Monday, April 20, 2009

• 9:00 am:  Eric Rux   The Big One – Merging 2 Companies!
• 10:15 am: Break
• 10:30 am: Nathan Winters  The Future of Email: Exchange 14 and Online Services
• 11:45 am:  Lunch
• 1:00 pm:   James Summerlin  SQL Reporting Services
• 2:15 pm:   Break
• 2:30 pm:   Roger Grimes  How I Fixed the Internets!
• 3:45 pm:   Break
• 4:00 pm:   Todd Lammle    TBA
• 5:30 pm:   Dinner organized with coach transport

Tuesday, April 21, 2009

• 9:00 am:   Rhonda Layfield  Windows 7
• 10:15 am:  Break
• 10:30 am: Mini Session A  TBD
• 10:55 am: Mini Session B  TBD
• 11:20 am: Mini Session C  TBD
• 11:45 am: Lunch
• 1:00 pm:  Mark Minasi   More Windows 7
• 2:15 pm:   Break
• 2:30 pm:   Curt Spanburgh   Hybrid Solutions, SaaS
• 3:45 pm:   Break
• 4:00 pm:   TBD  Light Session (Photography or other topic)
• 5:30 pm:    ‘No Host’ dinner at local restaurant  (one last chance to rub elbows with people in the know)
• 6:30 pm:    Vendor Evening – Details TBD – An evening with various vendors either on site or via Web conference, to look at relevant products.

Wednesday, April 22, 2009

• 9:00 am:   Stacy Hein  SQL for the Windows Administrators
• 10:15 am:  Break
• 10:30 am:  Joe McGlynn   SBS 2008 for the Small Business
• 11:45 am:   Closing thoughts and summing up
• 12:00 pm:  Final Lunch
• 1:00 pm:    Round Table Discussion

You can register by following the instructions on the site.  Oh yeah, that is me following Mark on the opening day, talking about Hyper-V 🙂  And local guy Joe McGlynn is also speaking on the Wednesday about SBS 2008.

Other speakers include MVP’s Nathan Winters, Curt Spanburgh, Rhonda Layfield and Eric Rux.  James Summerlin is the rarest of creatures: a developer and an IT pro!  Todd Lammle is a well known Cisco author, trainer, speaker and consultant.  Those of us from year 1 still shake from when he scared us with his IPv6 talk.  Roger Grimes is a security expert with 7 books to his name.  Stacy Hein is a SQL wizard well known to us on the forum.  And Mark Minasi is the famous author, speaker, trainer and consultant specialising in AD and Windows.

We had a hardware issue recently where we need to service the hardware of one of our Hyper-V cluster hosts.  The HP engineer originally believed there was an issue with the server’s motherboard so this needed to be replaced.  So it was.  This didn’t fix the problem – it turned out to be something else but that’s a tangent.

When the server was fixed we brought it back online.  Thanks to us using diskless blades and HP Virtual Connect, the OS and the data are stored on our fibre channel SAN.  Nothing was damaged.  The server started up and I tested VM failover using VMM.  I was getting a failure of:

"Error (2915)
The WS-Management service cannot process the request. Object not found on the myserver.domain.internal server.
(Unknown error (0x80338000))

Recommended Action
Ensure that the agent is installed and running. If the error persists, reboot myserver.domain.internal and then try the operation again."

To debug I went into the Failover Cluster MMC.  I expanded the service (VM) I was testing and expanded the properties.  I failed it over.  I could see the state saving and the disk going offline.  However, the configuration would fail.  The cluster would then move the VM to a working host.  I tried a few more VM’s and then I had some luck.  A VM stayed on the "bad" host after failing.

I went into the Hyper-V MMC and tried to start the VM there.  I was told that:

"The virtual machine could not start because the hypervisor is not running".

Ah!  The penny had dropped?  There are two BIOS requirements for Hyper-V to work.  CPU virtualisation assistance and DEP must be enabled.  In a HP Proliant, they are in something like Advanced – Processor Options.  My motherboard had been replaced, flashed with an upgrade and the old settings would be in the replaced motherboard.  I enable the settings (requiring a reboot) and fired up the box. 

All was now well.  I could move VM’s with no issue.

BTW, if you will have a node offline in a cluster for some time then you need to be aware of your cluster quorum settings.  Clusters with even numbers of nodes need a quorum and those with uneven numbers must not have a quorum.  I keep a quorum disk in place just in case a node is going to be added/removed from the cluster.  In our scenario, we had N+2 fault tolerance so I could afford to safely remove this node and alter the quorum settings without losing fault tolerance.

It is possible to convert a dynamic virtual hard disk (VHD) to a fixed size VHD.  I found myself doing this when I needed to migrate a machine from an R&D environment to production.  Note that the VM (if the disk is attached to a VM) must be powered off to do this.

If you use Hyper-V without Virtual Machine Manager 2008 then you can do this using the Hyper-V console.  Edit the virtual machine in question (if applicable), select the disk and click on <EDIT>.  Choose to convert the disk.  You’ll then be asked where to place the new disk.  Be wary here if you use dedicated volumes for each VM, e.g. in a Windows 2008 cluster.  There may not be enough disk space in the existing disks volume for the new fixed sized disk that will be created – that’s correct; it doesn’t convert the disk, it creates a new one.  Choose a suitable temporary location and name.  For example, my VHD might be called Disk0.VHD and I’d convert to Disk0Full.vhd.  When finished, I’d rename them, e.g. Disk0.VHD -> DiskDyn.VHD and Disk0Full.VHD -> Disk0.VHD.  Swap the files and then restart the VM.

It’s both easier and more complex using VMM.  You can select the VM in question and select the disk.  Tick the box for "Convert to Fixed Type Virtual Hard Disk" and apply the changes.  A new job will start.  This creates a new VHD in the same volume as the existing VM.  That’s a bit nasty.  You tend to limit the size of the LUN in question to avoid wastage when using a cluster.  So odds are, this will fail unless you’ve plenty of spare space in the LUN – remember the LUN will contain both the original dynamic disk and the converted fixed size disk for at least a short period of time.  Temporarily increasing and decreasing the volume size should not be done, even if your SAN can do it … my testing phase showed that it corrupts the contents of the volume.  The nice bit of this process is that all the file renaming and swapping is done for you.  I just wish you could pick a temporary location for the file conversion process.  That might be possible using PowerShell.