ESXi 5.0 To avoid the rather complex set of instructions that you needed to follow in 4.1, VMware introduced new detach and unmount operations to the vSphere UI & the CLI. As per KB 2004605 , to avoid an APD condition in 5.0, all you need to do now is to detach the device from the ESX. This will automatically unmount the VMFS volume first. If there are objects still using the datastore, you will be informed. You no longer have to mess about creating and deleting rules in the PSA to do this safely. The steps now are: Unregister all objects from the datastore including VMs and Templates Ensure that no 3rd party tools are accessing the datastore Ensure that no vSphere features, such as Storage I/O Control or Storage DRS, are using the device Detach the device from the ESX host; this will also initiate an unmount operation Physically unpresent the LUN from the ESX host using the appropriate array tools Rescan the SAN
No matter how sophisticated the technology is , It still takes people !