A volume pair consists of a P-VOL and one to three layer-1 (L1) pair S-VOLs.
Because S-VOLs are updated asynchronously, the P-VOL and S-VOLs might not be identical except immediately after a split. If a pair is split, any further updates to the P-VOL will not be reflected in the S-VOL.
Splitting or deleting a pair allows the host access to the S-VOL.