Hitachi USP V - Shadowimage Cascading Pairs

Figure 6-3 ShadowImage duplicated mirrors
ShadowImage cascading pairs
ShadowImage provides a cascading function for the ShadowImage S-VOL.
Cascading mirror volumes can be specified up to the maximum quantity 2.
The cascading mirrors of the S-VOL are expressed as virtual volumes using
the mirror descriptors (MU#1-2) in the configuration diagram as shown
below. The MU#0 of a mirror descriptor is used for connection of the S-VOL.
Data replication operations with CCI
6-7
Command Control Interface User and Reference Guide