Checking that a VM has the VMware Balloon driver running with esxtop

 

To check that your VMs have loaded and are running the VMware Memory Balloon driver in the guest OS, you can use esxtop.

 

  • Connect to your ESXi host using vMA, the DCUI or PuTTy (needs SSH service running) and run esxtop.
  • Switch to the Memory page (press M)
  • Press F to add a field
  • Press J to add the field “MCTL = MEM Ctl (MB)”
  • Press space to return to the main memory view page of esxtop.
  • In the new MCTL? column, look at the list of VMs – a “Y”  means that the driver is loaded and running whereas a “N” means that the balloon driver is not present.

 

This can be useful to double check things if you run into a problem troubleshooting memory ballooning issues as I have seen cases where VMware Tools reports as “OK” for the VM but the balloon driver is not running when viewed in esxtop.