Just another day in paradise

How do I find HyperV VMs with active snapshots?

Luke — Mon, 16 Jan 2012 13:24:22 +0000

Easy, script it with powershell!

I’ve attached my powershell script, use it as you wish and if you have any enhancements, send them through and I’ll update it. Just rename to .ps1

findvmsnapshots powershell script

Watch out for those growing .AVHD files

Luke — Thu, 29 Dec 2011 13:10:23 +0000

A commonly overlooked task in the snapshot procedure is the merging process after deleting an older point-in-time snapshot. By selecting the previous point-in-time snapshot and selecting Delete, the virtual machine continues without interruption.

At the file level, however, that .AVHD file still exists in the snapshots folder and will continue to grow. To return to your original VHD file, shut down the guest. At this point, the .AVHD file will merge into the VHD file and be deleted automatically. Depending on the size of the .AVHD this can take some time so you will need to do this at an appropriate time.

Live Migration and Dymanic Memory make sweet love

Luke — Fri, 22 Jul 2011 00:40:01 +0000

Recently I’ve been doing a lot of work with HyperV clustering, new HP DL380 G7 servers, and Netapp storage. One of the great features I’ve uncovered is the sweetness dynamic memory adds when doing live migrations. If you are not sure what Dynamic memory is you can have a read here.

Essentially when doing a HyperV Live Migration with Dynamic memory enabled on the virtual machine, the migration process only has to copy the USED memory pages to the other host. So if you virtual machine has 512MB startup and maximum 4096MB memory configured and is using 640MB of memory, it will only have to Live Migrate 640MB.

This means the Live Migration process is super quick and over a 1GB Live Migration network I have seen 10 sec live migrations occur regularly.

Happy migrating!

Is my application secure if I publish it via Citrix Xenapp?

Luke — Mon, 27 Jun 2011 15:19:48 +0000

Not necessarily…..especially Microsoft Excel.

Applications still run in the user context on the Xenapp server however all the user is seeing is the application UI.

Excel and other apps which allow you to write macros pose an interesting problem…you can write a macro to spawn processes/applications from the server, here is some example code;

Sub Testing()

Dim RetVal

RetVal = Shell(“c:\windows\system32\cmd.exe”, 1)

RetVal = Shell(“c:\windows\explorer.exe”, 1)

RetVal = Shell(“C:\Windows\System32\WindowsPowerShell\v1.0\powershell.exe”, 1)

RetVal = Shell(“C:\Windows\System32\regedit.exe, 1)

End Sub

So if the Xenapp server isnt locked down using group policy then you’ve just opened yourself up for a whole world of “comeandhackmyass”.

A good resource for group policy is Group Policy Center.

Credit to Dave Taylor for giving me the information for this macro code

Enable only specific items in group policy Windows 2008 R2

Luke — Mon, 27 Jun 2011 09:02:56 +0000

If you’re in a terminal server environment and want to look at locking down the control panel, there is a nice GP setting which allows you to only show specific Control Panel items – User Config\Admin Templates\Control Panel “Show only specific Control Panel items”

However, trying to get this full list of names to plug into the GP setting I found to be a bit of a nightmare, until I found this MSDN page.

Citrix License Administration Console is not enabled after upgrading to v11.9

Luke — Wed, 15 Jun 2011 13:01:49 +0000

After upgrading my Licensing server to version 11.9 from 11.6 I found some weirdness.

The installer seems to go ok, it comes up with a couple messages about having to reboot to update files, so naturally after the installer has finished I reboot which is where the fun starts.

I then find that the following services have been stopped and disabled – Citrix Licensing, Citrix Licensing Config, Citrix Licensing Support Service. Additionally I try the LAC Management console and receive the following error.

Wicked.

So to fix this little problem I carried out the following steps;

- enabled and started all the services above

- CHANGED the shortcut of the LAC Management Console to point to http://:8083 instead of localhost.

Hope this helps someone, took me 3 reinstalls and reverting to snapshots to work out what it was doing

UPN login doesn’t work with UAG 2010

Luke — Mon, 06 Jun 2011 01:51:07 +0000

That is because by default, this is not enabled but here is how you do it - http://technet.microsoft.com/en-us/library/ff607424.aspx

SCOM 2007 R2 CU4 agents not showing correct CU in SCOM console

Luke — Sun, 05 Jun 2011 13:53:33 +0000

What I found is trying to update my agents from CU2 to CU4 resulted in a common result, the agent would look like it had updated ok but when you check the SCOM agent for the agent version, it would still report CU2.

There is some information regarding updating of agents from CU3 to CU4 failing and a reboot and repair of the installation would fix this false reporting in the SCOM console. I did not find this fixed my issue when all my agents are on CU2. To fix the issue the only resolution I found was as follows;

- uninstall the existing scom agent

- install the scom agent from the scom server agent directory (this installs the scom agent with no CU)

- reboot the server

- apply CU4

I have tried a number of combinations before resorting to uninstalling the agent but none of them resulted in a fix.

Windows application page faults

Luke — Sun, 05 Jun 2011 07:16:45 +0000

Something which is important when determining if your service or application is having issue is Page Faults.

This is a great post explaining what they are and how they can be bad for your Windows server – http://blogs.technet.com/b/askperf/archive/2008/06/10/the-basics-of-page-faults.aspx

Unable to install SCOM 2007 R2 CU3 or CU4

Luke — Wed, 01 Jun 2011 06:37:45 +0000

When you try and install these updates on a Windows 2003 server which is your RMS server, you may receive the following error

“Tthe system administrator has set policies to prevent this installation”

This is because in CU3 and 4 SCOM now has the updates for the cross platform components baked into the MSI and the MSI is now quite large, 1.2 and 1.3GB respectively. There is a hotfix for Windows 2003 required to enable you to install MSI which are of a large nature, the update can be found here - http://support.microsoft.com/kb/925336

Once you install the update, reboot and run CU3 or CU4 again and happy days.

If you need help with CU4, this is a good place to start - http://blogs.technet.com/b/kevinholman/archive/2011/02/01/opsmgr-2007-r2-cu4-rollup-hotfix-ships-and-my-experience-installing-it.aspx. Please also make note there is a know bug with installing update CU4 SCOM agents on systems, read the blog post carefully.