High CPU Usage

I have a server that is a virtual machine under VMware 5.1 running Server 2012R2, its a terminal server that 20 or so users connect to, they run office 2013 and a custom application. Lately we have noticed that the CPU is running at 99-100% for prolonged periods, it appears to be the custom app that is causing it and I am in talks with their support, just wondering if there is any tweaking I can do on the windows or VMware side to make sure things are set correctly. The vm is configured with one socket and four virtual cores and 16GB of RAM, its running a Dell PE 620 on RAID 10.

There really isn't much you can do here from a VMWare level, but I would say that the VM is undersized for 20 users if they are especially using Outlook. Outlook is pretty heavy to run in general and will grind that poor server to a halt. I would recommend bumping RAM and CPU if possible. I would also make sure that the SCSI controller is set to Paravirtual for best performance, and the VM version is also at least version 8.

I think we found the culprit, a setting in the custom application, will know for sure tomorrow.

Thanks

DermicSavage said:

There really isn't much you can do here from a VMWare level, but I would say that the VM is undersized for 20 users if they are especially using Outlook. Outlook is pretty heavy to run in general and will grind that poor server to a halt. I would recommend bumping RAM and CPU if possible. I would also make sure that the SCSI controller is set to Paravirtual for best performance, and the VM version is also at least version 8.

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I am curious as to why you would recommend using paravirtual? It is my understanding that paravirtual should be used with higher IOPS such as databases, not for RDS. I have quite a few RDSH servers running Windows Server 2012 R2. Each have 8 vCPU and 32 GB of memory and averages about 25 users. The IOPS averages about 200 throughout the day.

KapsZ28 said:

I am curious as to why you would recommend using paravirtual? It is my understanding that paravirtual should be used with higher IOPS such as databases, not for RDS. I have quite a few RDSH servers running Windows Server 2012 R2. Each have 8 vCPU and 32 GB of memory and averages about 25 users. The IOPS averages about 200 throughout the day.

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It's standard best practice for VMWare VMs. Granted the difference is minimal if your VM is a low workload, it does remove more of the overhead processing required when those VMs access the disk. For a system that avergaes 200 IOPs in a day, you would likely never notice the difference.

Still, it's easy enough to set up into your templates to ensure it is standardized.