When removing a disk from a virtual machine using the vSphere Client, you have two options.
Each option works as follows:
Remove device
This option removes a disk from a virtual machine, but does not delete the vmdk file from the datastore.
Remove device and data
This option removes a disk from a virtual machine and also deletes the vmdk file from the datastore.
When you select Remove device to remove a disk from a virtual machine, the vmdk file remains.
To completely remove it, you must delete the vmdk file.
For example, the vmdk file is stored in a folder with the same name as the virtual machine within the datastore.
Select the vmdk file you wish to delete, then choose “Delete” from the menu.