Monitoring ESX Storage using "esxtop"

To monitor storage performance per HBA:

1. Start esxtop by typing esxtop at the command line.
2. Press d to switch to disk view (HBA mode).
3. Press f to modify the fields that are displayed.
4. Press b, c, d, e, h, and j to toggle the fields and press Enter.
5. Press s, then 2 to alter the update time to every 2 seconds and press Enter.

To monitor storage performance on a per-LUN basis:

1. Start esxtop by typing esxtop from the command line.
2. Press u to switch to disk view (LUN mode).
3. Press f to modify the fields that are displayed.
4. Press b, c, f, and h to toggle the fields and press Enter.
5. Press s, then 2 to alter the update time to every 2 seconds and press Enter.

 

To monitor storage performance on a per-virtual machine basis:

1. Start esxtop by typing esxtop at the command line.
2. Type v to switch to disk view (virtual machine mode).
3. Press f to modify the fields that are displayed.
4. Press b, d, e, h, and j to toggle the fields and press Enter.
5. Press s, then 2 to alter the update time to every 2 seconds and press Enter.
    

Analyzing esxtop columns

This table lists the relevant columns and a brief description of these values:

Column	Description
CMDS/s	This is the number of IOPS (Input/Output Operations Per Second) being sent to or coming from the device or virtual machine being monitored
DAVG/cmd	This is the average response time in milliseconds per command being sent to the device
KAVG/cmd	This is the amount of time the command spends in the VMkernel
GAVG/cmd	This is the response time as it is perceived by the guest operating system. This number is calculated with the formula: DAVG + KAVG = GAVG