I spend the best part of the day troubleshooting 2 Citrix servers, one only a Web Interface and the other playing a XenApp 6.0 and DR Web Interface role.  I couldn’t understand how in less than a hour after a reboot that a server with a single Citrix session could use 4GB of physical memory. I’ve been reading up on ESX recommendations for Citrix in terms of CPU and memory, i even increase the memory and CPU but really what difference would it make?!!? None.. it would still use 4GB.

In my troubleshooting steps I looked at all the running processes that were running for all user but couldn’t see what was taking up 4GB. I decided to check all the applications installed in the servers, the Web Interface server only needs the bare essentials for it to function. During the clean up I monitored the task manager, I then came across Microsoft .Net 4.0 Client and Extensions. I decided that we don’t need this version of Microsoft .NET and .NET 3.5 SP1 would work just fine.

During the un-installation on .NET Extensions I saw the memory fall rapidly down to a nice 700MB.

I’m now installing Microsoft .NET 3.5 SP1 and will watch for a few days.