Unlike esxtop, which collects real-time data, the vscsiStats tool is used to gather the I/O statistics of a VM at a per-virtual-disk (VMDK) level. It can collect statistics such as the number of outstanding I/Os, size of the I/Os, and seek distance and latency.
You will need access to the ESXi CLI via the console or SSH. Also, make note of the World IDs corresponding to the VMs you would like to fetch the statistics for. The esxcli vm process list command will list all the running VMs with their World IDs.
To fetch the I/O statistics corresponding to a VM, you will need to find the worldGroupID corresponding to the VM. This is achieved by issuing the following command:
# vscsiStats –l
Consider the following screenshot:
Now, this will be a huge list if you have a lot of VMs running on the host. If that is the case, then there are several ways to filter the list. One of them would be to send the output of the command to a...