Showing posts with label VDA. Show all posts
Showing posts with label VDA. Show all posts

February 8, 2023

Windows Pagefile Done Right

Over the years there has been a lot of information on configuring the pagefile, paging has gone through the evolution on what size and configuration it should be. With virtual machine RAM allocation going higher and higher and a lot of guidance from the likes of Citrix and VMware to potentially build VMs with 64GB+ RAM. Paging is a very interesting topic as setting the pagefile size too high, wastes disk space; removing the page file entirely is bad as well as Windows needs to have a pagefile even though we do not want the system to page. Not having a pagefile equates Windows complaining about not having enough virtual memory if the actual memory is fully allocated. While no one wants to page and systems should be built to minimize paging aka allocating enough memory to let folks operate their applications without paging but systems should be configured to allow some sort of paging as a "use in case" measure. Lastly the out of box configuration of a system managed pagefile is also a bad idea.

Setting the pagefile to system managed in an enterprise type of environment is a bad practice. The reason why? If there are any monitoring tools a lot of monitoring tools track pagefile utilization and it is typically tracked as a percentage. If the pagefile is set to system managed and the minimum/maximum are not set, it can result in monitoring tools reporting excessive pagefile utilization.

Setting the pagefile with the old school approach of setting the pagefile 1.5x the size of the memory results in this configuration. We will hear a lot of complaints about wanting to capture some sort of dump for Microsoft to "analyze". When was the last time Microsoft successfully analyzed a dump with meaningful results? For me it has never happened.

Here is what the drives would look like if we for instance allocated 64GB of RAM to a VM and are using the old school approach of 1.5x RAM for the pagefile:

Here is the error in the eventlog when the pagefile is completely eliminated as virtual memory is low:

What is the happy medium? Setting the pagefile to either 4096MB/4GB for both the minimum and maximum on single user operating systems and 8192MB/8GB for both the minimum maximum on multi-user operating systems.


Why is this the happy medium? I checks all of the boxes as it allows for Windows to have a pagefile if needed, it allows for a minidump to be configured/captured/analyzed in Windows if needed and it is not too large that we feel like we are wasting space.

What about memory dumps? Well if there is a need for some sort of memory dump to be captured and analyzed, Windows can be configured to generate a minidump. There are plenty or articles/blog posts out on the internet on how to configure Windows to produce a minidump.

If you have any thoughts, we would like to hear from you in the comments.

Johnny @mrjohnnyma

April 16, 2019

Citrix VDA Install Error - Unable to start Setup

Purpose:
 
This post is to explain how to fix the "Unable to start Setup. Please check your installation media and try again" error when installing the Server VDA with Desktop Flag.


Symptom:

During the installation of the VDA the below error comes up


Check the VDA install log (xendesktop installation.log) in this location
C:\Users\username\appdata\local\temp\citrix\xendesktop installer

You'll see the below error in the log "Server VDI cannot be installed if Windows Remote Desktop Service Roles are installed"





Resolution:

Remove the Remote Desktop Session Host Role and reboot the VM.
Once the VM is rebooted attempt the installation again


Cause:

The Remote Desktop Session Host role is installed and it can't be present for a Server VDI VDA installation.

SageLike Post ID: SL0022

Applies to:

Windows Server VDA's and installing the VDI VDA that previously had the Server VDA installed.   

December 5, 2018

Citrix Receiver - Azure Servers - TCP Resets Client Side

Purpose:

This post explains an issue that occurred to me when trying to establish connections to Citrix VDAs (Server 2016) in Azure. Within our environment we have a VPN tunnel to connect our primary datacenter to our Azure tenant. The VPN tunnel is a very important piece to this puzzle.

Symptom:

Once the VDA is built, they are registering to the Delivery Controllers and apps/desktops are published you are attempt to establish a connection via published app or desktop the client has issues keeping the connection. Specifically once the application/desktop is launched, Citrix receiver/workspace launches and tries to establish a connection and gets stuck at "Connection in progress...."



Reviewing network trace logs through firewalls and wireshark you will notice TCP Resets on the client side.


Resolution:

The easiest option here is to disable Enlightened Data Transport aka HDX Adaptive Transport within the Citrix Studio policies for the delivery group(s) that are hosted on Azure.



Cause:
This article details it best but the primary reason is because of IP fragmentation isn't handled correctly over the VPN tunnel. Disabling EDT addresses this issue.

https://support.citrix.com/article/CTX231821

As of right now I don't have a way to get this to work correctly if you want EDT turned on.


SageLike Post ID: SL0021

Applies to:

Citrix VDA's hosted within Azure that has a VPN tunnel connecting Azure to the on-premise infrastructure.

References:
https://support.citrix.com/article/CTX231821