How To Unmount A “Busy” VMFS Datastore In vSphere 5.5+

I recently ran into an issue where I was could not unmount an empty vSphere datastore from the appropriate hosts. After doing some research I found out that this issue was caused by open files from a new VSAN-related service known as “vsantraced”. According to this VMware KB article, you must perform the following steps in order to unmount the affected datastore(s):

  • Login to the vSphere host via SSH
  • Stop the “vsantraced” service
    /etc/init.d/vsantraced stop
  • Unmount the datastore(s)
  • Start the “vsantraced” service
    /etc/init.d/vsantraced start
For more details please see the VMware KB article linked to above.