When you create a ShadowImage pair, the storage system performs an initial copy operation to copy the data in the P-VOL to the S-VOL. You can create a pair and then immediately split the pair to gain access to the S-VOL. You can also create cascaded pairs in which the S-VOL of a layer-1 (L1) pair functions as the P-VOL of a layer-2 (L2) pair. The maximum number of layers is two.
When you create a ShadowImage pair, the MP unit assigned to the P-VOL is also assigned as the MP unit for the S-VOL.