3DC cascade configuration requirements and cautions

• One VSP G800, VSP F800, or VSP G1000 is required at the each of the three sites of primary, intermediate, and secondary. When there is more than one storage system at each site, the 3DC cascade cannot be configured.

• CCI is recommended at all three sites.

• Device Manager - Storage Navigator is required at all three sites.

• The primary site requires the following:

• Host application

• TrueCopy

• TC primary volume (P-VOL), the primary production volume

• The TC P-VOL fence level (Primary Volume Fence Level) must be Secondary Volume Data.

• The intermediate site requires the following:

• TrueCopy

• Universal Replicator

• TC S-VOL, which is also the UR P-VOL

• UR master journal

• The secondary site requires the following:

• Universal Replicator

• UR S-VOL

• UR restore journal

• Differential data is used to resynchronize a suspended TC or UR pair.

• When the TC pair is resynchronized, the UR pair in PAIR or COPY status is automatically split by the system.