VMware – esxtop – troubleshooting VM CPU performance

To display VM only press V (VM only view):

then to expand specific VM press e (expand) then enter the GID number:

As this VM has 3 CPU I can see CPU usage on all of them, RDY, USED and CSTP times.

%RDY is a Key Performance Indicator!  This one defines how much time your virtual machine wanted to execute CPU cycles but could not get access to the physical CPU. It tells you how much time did you spend in a “queue”. I normally expect this value to be better than 5%. In this case we can see that this VM is struggling a bit or it is very busy.

%USED tells you how much time did the virtual machine spend executing CPU cycles on the physical CPU.

%CSTP tells you how much time a virtual machine is waiting for a virtual machine with multiple vCPU to catch up. If this number is higher than 3% you should consider lowering the amount of vCPU in your virtual machine.