All posts tagged Windows

We are using Hyper-V for virtualization. We have several Hyper-V clusters running hundreds of VMs. From time to time there is a need to the reboot Hyper-V host servers usually when we push updates to them or sometimes just to refresh them. We all know that Window OS likes regular reboots to refresh itself.

So, whenever we needed to reboot the host servers, we had to do them manually. The steps we had to do are:

  • Pause” first host/node and “Drain” roles
  • Once it is in “Pause” state, reboot it and wait for it come online
  • When the host is online, “Resume” it and move to the next host

This was a time consuming task therefore I decided to develop a script to automate this task. The script is attached and you can download and use it if you want.

Now let me explain a bit what this script does. As you can see I have added some output commands so we can we can monitor the execution and see what is being done at each step. The script takes the cluster name as an argument. You run the script using the command below:

.\RebootClusterHosts.ps1 -Cluster "ClusterName"

Replace the above “ClusterName” with the name of your cluster. At first the script gets a list of all the nodes in the cluster and then goes into a “for” loop to process each node. It firsts check if the node is up (there maybe one or more nodes down because of any issues or maintenance), if that node is not up then it skips it and moves to the next node. If the node is up, it starts the process to Drain the Roles/VMs from the node and pause it. It then waits until all the Roles/VMs are drained and the node is paused. When this process is complete, the script waits for 5 seconds before reading the status of the node (I added a “sleep” for 5 seconds just to give it a few more time to refresh). After that it checks the status of the process, it checks the node DrainStatus and node State. If DrainStatus is not “Complete” and State is not “Paused” that means something went wrong. We have seen issues where sometimes all the Roles/VMs are not successfully migrated to other nodes and this process fails. This is where the script prompts the user that draining was not successful and they need to drain the node manually and press [Enter] key when done, so the script execution can continue. So, here the user needs to drain the node manually, once done they can press [Enter] key.

If the draining was completed successfully, no user interaction is needed and the script continues to restart the node and then it waits for the node the come online. I added the switch to the Restart command to wait for PowerShell status to come online. I have seen that this check is not enough and sometimes the nodes take longer to fully become available after the reboot. That is why here I have also added a “sleep” for 15 seconds to give the node another 15 seconds. Then after that there is a while loop that checks the status of the node every 1 second until it becomes available. When the node becomes available, the script Resumes/UnPauses the node. I have used another while loop here where the script tries to resume the node and check it’s status after every 1 second until it’s status becomes “Up“. I have ran into the issue where sometimes trying to resume the node once did not go well therefore I added a while loop here.

When the node’s status becomes “Up” the script moves to the next node and does all that processing mentioned above on that node.

I have ran this script multiple times and have tuned it as I came across issues. You all are welcome to modify it according to your needs. If you find something that can be done better, please do let me know.

This script can be used for rebooting failover cluster hosts/nodes and not only Hyper-V cluster hosts/nodes.

Thanks all!

Download the script below.

At my work we are required to use Smart Card to login to our systems. It works fine as long as we are logging on to our Macs or our Windows Desktops. Even if we use Remote Desktop connection from our Windows desktops to other Windows machines, it works without any issues. The problem occurs when we try to logon to Windows machines from Macs. There aren’t many Remote Desktop client options available for Mac that support Smart Card redirection. Even Microsoft Remote Desktop client on Mac currently does not support Smart Card redirection. I found a nice client Royal TSX that supports Smart Card redirection and it works fine. Actually it worked fine until Windows 7 and Windows 2012 Server. It stopped working with Windows 8 and Windows 2012 R2. It looks like Microsoft has changed the behavior of Smart Card service in Windows 8 and Windows 2012 R2. When I try to logon to Windows 2012 R2 Server or Windows 8 from Mac using Remote Desktop, I get the error “No valid certificates were found on this smart card” as shown below.

hmmm. The workaround I used for this was to connect to my Windows 7 Virtual Desktop and from there connect to Windows 8, Windows 10 or Windows 2012 R2 machines. This was an ok workaround until recently when my Virtual Desktop was upgraded to Windows 10. I was expecting that this Smart Card issue would have been resolved in Windows 10 but Windows 10 has the same issue. After doing some research online I found out that Microsoft has changed how Smart Card service behaves in Windows 8 and later. The Smart Card service only starts when it detects the Smart Card reader. It looks like when I Remote Desktop from Mac to the Windows machine the Windows machine is unable to detect the Smart Card and therefore the service does not start. I tested it by manually starting the Smart Card service and I was then able to logon to the machine. Now the problem is how can I make sure to start the service when I am connecting via Remote Desktop. I noticed that when I connect using Remote Desktop, the event viewer logs an event “9027” in Application Logs, as shown below.

Now I think that I can use this event and use task scheduler to start the Smart Card service whenever there is this event in the Application Log.

I started the Task Scheduler and created a new Task by using the steps below.

Start Task Scheduler, right-click on Task Scheduler Library and then click on Create Task

Name the task whatever you want, I used “Start Smart Card Service”.

Make sure to use the options as shown in the picture above.

“When running the task, use the following user account:” needs to be set to “SYSTEM”. We want this task to run as SYSTEM user.

“Run whether user is logged on or not” needs to be selected. We want this task to run whether any user is logged on or not.

“Run with highest privileges” needs to be checked. We want this task to run with highest privileges. The task may run fine without checking this box, but I just checked it so that it doesn’t fail because of the lack of any permissions etc.

Now go to “Triggers” tab

Here click on “New” button to create a new trigger. You will see the following window

Click on the dropbox next to “Begin the task:” and select “On an event”. We want to start the task on an event.

Now in the “Log:” dropbox, select Application

In the “Source:” dropbox, select “Desktop Window Manager”

and in the “Event ID:”, type “9027”.

We saw from the Event Viewer log that the log type of “Application”, Source is “Desktop Window Manager” and Event ID is “9027”. So, we want this task to run on this event only. Now click on “OK” and you will see this trigger added.

Now go to Actions tab

Click on “New” button to add an action.

In the “Program/script:”, type “net”. In the “Add arguments (optional):”, type “start scardsvr”. i.e. we want to run “net start scardsvr” to start the Smart Card service. Now click on “OK” to close this window. Everything else can be left as default so you can click on “OK” again to close the properties window.

Now your task is setup and will show up in the list of tasks. This task should start the Smart Card service whenever you connect using Remote Desktop Connection.

Try it, when you connect using Remote Desktop, it should now read the smart card and ask you to enter your PIN, after entering the PIN you should be able to logon to your Windows 10 machine. If it doesn’t work, try taking out the smart card and inserting it again.

Now this resolved my issue with connecting to my Windows 10 Virtual Desktop from my Mac Desktop. But later on I faced another issue, when I lock my Windows 10 machine, after sometime it stops accepting my Smart Card and gives me either “No valid certificates were found on this smart card” or “The requested key container does not exist on the smart card” error. I haven’t found a workaround for this and am still looking to see what event it generates to maybe trigger my task on that event too. But for now, whenever I receive these errors while trying to unlock my Windows 10 machine, I just disconnect the session and reconnect and it works fine. I will update my post if I am able to develop a workaround for this.

This workaround should work on Windows 2012 R2 also, the difference is that Windows 2012 R2 server may generate some other event in the event log other than “9027” and you would have to look for that and configure your task to trigger on that event instead.

If you need help, please don’t hesitate to contact me. I would also like to request that if you find a better workaround, please let me know.

Until Microsoft or Apple (whoevers the issue is) resolves this issue, I am using this workaround.


Thanks for reading my post!