Thin Image Advanced pairs are configured as shown in the following figure, based on the number of snapshot datasets for the P-VOL or the number of the S-VOLs assigned to snapshot datasets.
When you create a Thin Image Advanced pair, a mirror unit number (MU number) is assigned to each snapshot data.
You can perform Thin Image Advanced pair operations by specifying an MU number. An MU number is assigned in the range from 0 to 1,023. If you create a pair without specifying an MU number, the MU number is automatically assigned in the following assignment order.
For a P-VOL, the unique number is assigned to each snapshot data for the P-VOL in the order of 3 to 1023, followed by 0 to 2. For other P-VOLs, the number unique within each P-VOL is assigned to each snapshot data for each P-VOL in the same way.
In the same way, in a cascade configuration, the unique number is assigned to each node volume under the root volume. The number unique within the node volume is assigned to each leaf volume under the node volume.