Grayed Out Disk Cache Size in Citrix MCS – XenApp 7.15 LTSR

To all the people out there who had issues when trying to create a machine catalog on versions above 7.9 and wondered why the Disk Cache option is greyed out, here is a potential answer to that issue. This is exactly what I ran into while recreating the catalogs for a customer who wanted to expand their disk space for their XenApp workloads. As you probably might know, the only way to expand the C drive space is by recreating the machine catalog.

XenApp version is 7.15 LTSR which was deployed originally as XenApp 7.5 and later upgraded to 7.15 LTSR version meaning that the original catalogs weren’t created using MCSIO.

The catalogs that needed Citrix MCSIO turned ON didn’t have the disk cache feature alive in the Catalog creation wizard. See the picture below.

Citrix MCSIO was first introduced in XenApp 7.9 which was supposed to be an alternative to PVS’s own memory cache feature. It is still debatable that if MCS’s memory cache feature is as good as PVS, but admins these days have an alternative if they want to give their workloads a bit of performance boost while running MCS.

Now, back to the issue! The fix lies in the Hosting Node in Studio where you have/had configured the connection to your hypervisor. In my case, when they were originally created, there was no MCSIO feature around so never had storage options to turn ON back then.

You could either edit the existing Resources under existing Connections.

I chose to create a new Resource under an existing Connection.

You will basically need to choose a Cluster in your hypervisor farm and choose between Local and Shared storage.

Under Storage Selection, select the datastores for OS, PvD and Temporary Cache. Though PvD is deprecated, it doesnt let you progress unless PvD option is ticked.

Choose a Name for your Resource and select the Network Adapter.

Click Next

Click Finish at the Summary page.

Note – if your MCSIO driver version is older than, you will most likely have performance issues. I am running XenApp 7.15 LTSR CU3 which already has the above driver version.

Once you have setup your new Resource under Hosting node, head over to the Machine Catalog node in Studio.

Create a new Machine Catalog and you will see that the Disk Cache option is alive.

Hope this helps somebody out there!

Desktop Restart – Citrix Storefront Power Management

If you have noticed the Restart button for published desktops in Citrix Virtual Apps and Desktops 7 1912 LTSR recently and wondered why in the world Citrix would give users access to users to restart machines, you are not alone. Make no mistake, this is a perfectly fine setting to be enabled out-of-the-box for VDI deployments where just Desktop OSes are being published or on the delivery group that contains Desktop OSes. You would want your users to be able to restart the desktop every now and then anyway.

Now after going through the Citrix SDK documentation, I found the below notes for the -AllowRestart argument that governs the restart button.

AllowRestart (System.Boolean) Indicates if the user can restart sessions delivered from the rule’s desktop group. Session restart is handled as follows: For sessions on single-session power-managed machines, the machine is powered off, and a new session launch request made; for sessions on multi-session machines, a logoff request is issued to the session, and a new session launch request made; otherwise the property is ignored.

So, it isn’t too bad to have that button available for RDSH delivery groups but should probably be called something else. The name “restart” has a negative vibe to it in multi-session world. lol

The option\button will appear like the below.

How would you remove the Restart option?

You will need to do this via Powershell.

asnp citrix*

Find the delivery group that has RDSH based published desktops and take a note of the Name parameter. You can do this on all the delivery groups if you want to disable this button for all published desktops, both RDSH and VDI.

Run the below command to find the value for the delivery group that you want to turn OFF the setting for. The parameter we are looking for is AllowRestart. When the value is True, Restart button is shown. Setting it to False will remove the button from Storefront.

Get-BrokerAccessPolicyRule -Name "XA-W2K16-DG-CORE_Direct_1"

Now, run the below command to turn off the Restart button

Set-BrokerAccessPolicyRule -Name "XA-W2K16-DG-CORE_Direct_1" -AllowRestart $False

You may need to do this for the AG version and Direct version of the delivery group.

Direct Version
Access Gateway version

Refresh the Storefront page via gateway and internally to see the results.

That’s all to it folks. Have a good one!

Microsoft DirectAccess breaks Citrix/XenApp application launches – Fix

If you have implemented DirectAccess for your users so that they could connect to corporate network whilst they work from home, you might have come across this issue while using Citrix. Users would be able to connect to Storefront portal and authenticate themselves but when they try to launch applications it fail. Users will also notice the below Citrix Receiver dialog with no apparent error messages.

The users who connect directly to Storefront without DirectAccess have no issues to launch applications.

The Cause

When you have DirectAccess enabled on user PCs, it expects hostname/FQDN values for initiating traffic between the client and the DA gateway. By default, Citrix XenApp tries to connect on IP addresses to bypass the infrastructure reliance on DNS. So, we will need to find a way to switch that behaviour to an FQDN based connection initiation.

Let’s look at the .ICA files to see what’s in there. The below screenshot is of an ICA file that shows IP addresses. This setup will NOT work for DirectAccess connections.

The Fix

To fix this, you will need to change a DNS parameter in XenApp/XenDesktop 7.x farms.

asnp citrix*

You will need to change the value from False to True

Set-BrokerSite -DnsResolutionEnabled $True

Running a Get-BrokerSite after that will show that the value has been changed from False to True

Now, let’s inspect the ICA file again. You can find the ICA files from your User profile folder. I had mine under

C:\Users\<username>\AppData\Local\Citrix\Web Helper v2\Temp

If you open the file in Notepad, you can see that the IP addresses have been replaced with FQDNs

That should resolve the issue.

Stay safe and Stay at home. Cheers people!!

Find the Total Unique & Peak Licenses Usage in XenApp/XenDesktop

Okay, this is going to be a short one and I came across this while investigating an issue for a customer who runs a XenApp 7.15 LTSR farm. Well, “Citrix Virtual Apps” as it is called these days. Citrix, what’s up with changing product names every year? you gotta stop doing this for God’s sake. Peace.

Here is the command. Firstly, load the Citrix cmdlets by running

asnp Citrix*

Now, the actual command to find the information


The result will look like the below

Look for the parameters marked in Yellow above – PeakConcurrentLicensesUsers & TotalUniqueLicenseUsers