What is vimtop? Vimtop is a command found on the vCenter appliance that can give you lots of performance related information. Just run vimtop without any options to run it interactively. This gives you cpu, memory and process information.
Vimtop has an "h" option for help. Press Escape once you are done looking at these options.
Vimtop has a "k" option for disk related information. Look for Read and Write operations.
Vimtop has an "o" option for network related information. Look for dropped packets.
"P" option = pauses the screen
"S" option = sets the refresh rate in seconds
"Q" option = quit vimtop