HP XP P9000 Command View Advanced Edition Software - Manual (Page 358)

As shown in Figure 11 , because there is a limit of three generations, the fourth generation must write
over one of the preexisting volumes. In this case, the oldest volume (generation 1) is overwritten.
Generations 5 and 6 follow the same pattern of overwriting the oldest, existing generation.
Figure 11 Backing up multiple generations
The order in which secondary volumes are used for backups does not change regardless of which
generation you might decide to restore at some point in time.
Figure 12 depicts how generations are
used.
TIP:
The number of generations that Replication Manager can manage depends on the volume replication
function and hardware used, but the same procedures are used for backup and restoration operations.
To determine the number of generations supported according to storage system and copy type, see
“
Copy pair configuration conditions ” on page 148.
Managing application replicas 358