Citrix Presentation 4.0 + vSphere 5 high cpu usage

[stevemayster]

Hello!
Our organization recently installed Sitrix Presentation Server on the server ESXI 5.0
Server Configuration Sun Fire X4200 2x2 CPU 32 GB memory
Virtual Machine Configuration 2x 2 vCPU, 16 GB memory
Number of users on the server 40-45 people at a time
The server registers a high CPU load (up to 100 percent)
Citrix Management Console shows an error (Processor% Interupt time)

Currently installed User Hive Profle Cleanup, disabled all visual effects. Use ACPI Multiprocessor
CPU load does not fall, often fails the server.

[AWo]

You have 4 cores in the host and assigned 4 vCPU's to the guest? That can lead to cpu contention. Try less vCPU's in the guest. I would try 2 vCPUs.

AWo

[stevemayster]

Hello.Thanks for answer

No i assigned 2 vCPU with 2 cores each.

Now i try to assigned 3 vCPU 1 core each.... things is going worse

[AWo]

Maybe you just have too less cores in the host for 40 - 50 users.

A rule of thumb says, assign 50% the number of cores as VCPUs to a guest at a maximum. I expect that the multiprocessoring got better with 5 again (need to look at), but it is still symmetric multiprocessoring. That means for several tasks the guest needs to acquire the number of cores you assigned as vCPUs. So it ha sto wait until these cores gets free. That slows the guest down. Then, when it has acquired the cores, all other guests can only run on the remaining cores. So if you assign 4 vCPUs while having 4 cores, all other guests must wait until the one guest frees the cores.

What does Citrix recommend for this number of users?

How many other guests are running on that host?

How many vCPUs do these other guests have?

AWo

[AWo]

Check that document:

http://www.vmware.com/pdf/Perf_Best_Practices_vSphere5.0.pdf

There are also some threads regarding best practises aroun in this community. Just use the search function...

AWo

[stevemayster]

I'm assing 2 vCPU with 2 cores.

Sweetpot of user on one server 30-40 session

Also on this host running 2 VM

They have 1vcpu with one core each

[vMario156]

Which operating system are you using for your Citrix Server?

Regards,

Mario

[stevemayster]

Windows 2003 SP2

[danpalacios]

We are running XenApp 5 on vSphere 5 and have similar issues.  In our research and testing we found that 2 vCPU /server was the sweet spot.  It gives multi-thread capability for handling a runaway process but limits the vSMP concerns.

In our attempt to improve performance, we also scheduled affinity to limit CPU Ready and context switching issues.  This helped but ultimately Terminal Service servers are subject to CPU contention.  The only information I could find when researching for sizing was that the number of users per server depends on the apps they run.  VMware also recommended going "wider not deeper".  In other words, deploy more VMs rather than stack more CPUs to try and crowd in more users.