Cannot Select the Location to Add a Virtual Disk (1402)
When you add a new virtual disk to an existing virtual machine, only a default location, as determined by VirtualCenter, is available.
If the default VMFS volume does not have sufficient disk space, the new virtual disk is not created.
If the disk is not created, no error message appears. Because adding a virtual disk is considered a long-running operation, and all long-running operations are tasks, the failure to create the disk shows up in the status of the task that was created under the Task tab.
Refer to the Task tab for the virtual machine. The status indicates whether or not the task of adding a virtual disk was successful. The default location is the VMFS volume where the original virtual disk is located. In the case of GSX Server hosted virtual machines, the new disk is created in the same directory as the virtual machine.
This issue is resolved in VirtualCenter version 1.1.1 or greater.