ESXi “esxtop” data can be huge, especially if you capture all columns. Not all metrics are equally important. Typically, for diagnosing performance in a VM environment, you want to focus on:
-
CPU Usage (e.g.,
%USED
,%RDY
,%CSTP
/ co-stop for SMP VMs, etc.)%RDY
(ready time) is a key metric to see if the VM is waiting for CPU.%CSTP
(co-stop) indicates scheduling delays for multi-vCPU VMs.
-
Memory Usage (e.g.,
MEMCTL
,MEM_ACTIVE
,MEM_CONSUMED
,MEM_OVERHEAD
) -
If memory is overcommitted, ballooning or swapping might occur.