Recently I have been working on a performance scan for a customer. The customer wanted to have a newly built XenApp 7.6 environment validated. Ofcourse I used Login VSI to do the task at hand. While starting the validation, the customer expected to reach about 80 concurrent users on one physical host (with 3 virtual XenApp servers on it).
After getting VSI to run in the environment I started a first small test, with 30 users to see what the enviroment did.
Bad antivirus configuration
After seeing this test and reaching VSI max at 25 sessions (which comes to 8,3 users per XenApp server) I went back to the customer and told them my findings. The first thing I noted in the analyzer was that the IO baseline was high as they were on an all flash environment. So I suggested they have a look at the anti-virus configuration and especially the exclusions.
Turned out the antivirus configuration just didn't get applied. A next test we made sure antivirus was disabled on the machines and ran the same test, didn't reach VSI max on that. So I ran a test with 100 users. With the followin result:
Good antivirus configuration
I was able to run 88 users without a problem on the servers (got a few stuck sessions because of an un-reliable outlook plugin making outlook crash).
The conclusion of the story. It is very important to have a good antivirus configuration for your VDI/SBC environment. Not only will it benefit the user density on your environment, it will also benefit the user experience on the environment.