Hi Andrew,  Please check first if you have any clones present in the array using command "Symclone list". If you are unable to see the devices in the clone list then there might be chances that Enguinity enables a Clone Tag for the particular device. I have faced similar kind of issue where we don't have any clones running, but there was clone tag enabled in some devices.  If this device is locked by the enguinity then you have to contact EMC to clear it. In case it is present in the symclone list details then you can follow the method provided by dynamox.
I have to remove 2 meta TDEV's from our VMAX array as they are no longer needed. The problem is that they are both showing as being Target Devices in a clone pair if i look at the output of symdev -sid show  so cannot be unbound from the storage pool and destroyed.  My knowledge of clones in VMAX is non-existent but everything i have read suggests you had to have a device group in order to create a cloned pair but running symdg -sid list  returns no device groups. So wonder if they could have been paired up manually? And if so can just be split manually and how would that best be done?  If anyone has any ideas or can advise if it's possible (and safe of course) to split up pairs manually somehow it would be really appreciated.
Split clone pair question