As a vSphere administrator, one of the most common tools I use for troubleshooting performance is ESXTOP, which I’m sure you’ve all heard of. Now with the release of vSphere 6.7 U3 and vSAN 6.7 U3, VMware has added a new VSANTOP command-line tool which runs on ESXi hosts to view real-time vSAN performance metrics.
VSANTOP allows you to monitor and troubleshoot vSAN related statistics at a very granular level in real-time. This handy new tool can help administrators and VMware support to troubleshoot issues with your vSAN environment.
There currently isn’t much documentation available on VSANTOP, so I decided to test this in my lab and share some useful usage tips and screenshots. Official documentation Using vsantop Command-Line Tool
I particularly like this tool because it’s simple to get started. Start an SSH session to one of the ESXi hosts in the vSAN cluster and type vsantop (in lower case), this will display the default entity type “host-domclient”
To display the different performance views and metrics in vsantop, enter the following commands:
|h or ?||Help; show this text|
|f / F||Add or remove fields|
|o / O||Change the order of displayed fields|
|s||Set the delay in seconds between updates|
|#||Set the number of instances to display|
|E||Change the selected entity type|
|L||Change the length of the field|
|l||Limit display to specific node id|
|.||Sort by column, same number twice to change sort order|
Press h or ? to show help and list of commands
To select a different entity, type E (Uppercase) To choose an entity, type the associated number ranging from 1 – 40 and press return/enter.
For example in my lab I wanted to see the entity vsan-vnic-net metric so I typed 39 and pressed enter.
Press f / F to view current visible fields or to add and remove metrics, you can display up to 10 fields.
Depending on the number of fields that are visible you may need to increase the size of the columns to make the metrics easier to read. This is where ^L comes in, type ^L to change the default size of 10, in this example I change it to 20.
You may also want to change the order of the fields, pressing o / O will allow you do this.
Below are some examples of other metrics I monitored in my lab.
I hope you found this post useful and now understand the basics of VSANTOP.
If you prefer to monitor vSAN performance stats from a graphical user interface, check out my other post on setting up the cool vSAN Performance Monitor Fling.