VM Application performance issues (Citrix)

[JKTAshgrove]

All,

I'm at my wits end, so hopefully someone here can help...

I have (3) VMWare clusters setup, one of which is a new VSphere cluster that contains (2) Dell R710 servers, the rest of the clusters are running ESX3.5 on older Dell HW. All clusters are connected to a EMC CX2-40 SAN. On my new clusters I have 4 VM servers connected running Windows 2003 R2, one of which is a Server with Citrix PS4.5...Eventually my goal is to migrate 10 Citrix servers, which are currently Dell Blades, to this cluster. Each server runs an application that has an average of about 15-20 users. Because of an existing need, I have already migrated one of the existing Citrix (Blade) servers to an older VMWare 3.5 Cluster and everything is running good. As mentioned earlier, I have created a new Citrix 4.5 Server on my new ESX 4 Cluster and this is where my problem lies...This new server is a single vCPU, 2048GB RAM and (2) 20GB partitions...The first partition is where all system files are stored and 2nd is where the Page file and app data is stored...On this server I have no production users setup as of yet, but we have been running tests using a few test accounts...One of my testers was complaining that the application was running slower than it should, but was very sporadic...He was originally running this through a Citrix session, but we also found the problem was the same if we ran it from the server console..The app seems to run fine for a few minutes, but then it will become unresponsive for a few seconds or it will take much longer to process a request..Even minimizing or closing the app seems to take a few seconds to complete. Using Windows Performance monitor, I have been monitoring what happens thinking maybe I have a Processor or a disk contention issue, but everything comes up normal...There are no spikes in CPU Utilization or Disk queues...I also have been checking Disk, CPU and Memory graphs in Vcenter, but everything looks normal (actually below, because there are basically no production VM's on this box) I also had a EMC Engineer come in and check to make sure there were no Disk Contention on the SAN and he says everything looks fine..

Any ideas what could be going on with the VM? I've followed the Best Practices for installing Citrix, but it seems that it happens even from the server console...Yet the VM itself gives me absolutely no indication of whats going on, in terms of performance issues..

Any help will be very much appreciated!!

[eknorr]

Have you tried to set a CPU reservation of 200mhz?

Eric

[JKTAshgrove]

Thanks for the quick response!!

No I haven't, didn't even occur to me since there isn't any CPU contention on the server...I assumed you only did that if there was a problem with CPU scheduling with multiple requests...

[eknorr]

Its not so much CPU contention - but having CPU cycles pre-committed before they are needed.

I have noticed an increase in respsoniveness in my terminal servers desktops after using the reservations.

Eric

[JKTAshgrove]

Thanks again Eric...I will give it a try...

[JDLangdon]

I've found that Citrix VM's, regardless of workload, will perform better with 2vCPU's.

________________________________

Jason D. Langdon

[JKTAshgrove]

I thank everyone for helping me out here!!!

I've tried CPU reservations and adding an additional CPU to the VM, but unfortunately didn't help me out...

I'm the furtherst thing from a developer, but this particular app is unique because it's sort of "moduler"...Meaning that every time a new window is opened your sort of opening a new instance of the app. This particular app is called "Avantis" and it's developed by a company called Wonderware...It's a manufacturing facility maintenance application, which includes Purchasing, Workorders, Inventory, etc...Each section is a different module and within each module there are different "views" to the data. So for each "view" I open, I open another instance of the module (I know makes NO sense).

The only reason I say this is because even though there can be many "instances" running in task manager, it's not very CPU intensive but more memory intensive... So I can open multiple instances and my CPU stays fairly idle, even when a module becomes unrepsonsive for a few seconds, there is no CPU spike, Memory spike or Disk spike.This is what's so frustrating!!

I will also say, when the app becomes unresponsive and I have task manager up, the app does go into a "not responding" state..But if I have say Word or Excel open, they are still in a running state.