Any operation that deletes the virtual LDEV ID of a volume used as a ShadowImage volume cannot be performed.
When a GAD pair is deleted with the P-VOL specified, the virtual LDEV ID of the S-VOL is deleted. If you delete the pair with the S-VOL specified, the virtual LDEV ID of the P-VOL is deleted. When the virtual LDEV ID is deleted, the server does not recognize the volume.