HP XP Racks - Manual (Page 42)

Please note the following when sharing Cnt Ac-S volumes with BC volumes.
•
L1 and L2 BC pairs can be shared with Cnt Ac-S volumes. Both node and leaf S-VOLs are
considered secondary volumes by Cnt Ac-S.
•
BC is recommended for in-system copy operations. However, if BC is not installed, Cnt Ac-S
can be used to copy within the same XP7. This configuration requires at least one fibre cable
loop.
•
The BC Quick Restore can be performed when the Cnt Ac-S pair is suspended. For information
about the Quick Restore operation, see the HP XP7 Business Copy User Guide.
Configurations with Business Copy P-VOLs
Cnt Ac-S can share a BC P-VOL in three configurations:
•
In the following figure, the Cnt Ac-S P-VOL also functions as an BC P-VOL. This configuration
allows you to use BC for on-site data backup in case of Cnt Ac-S failure. Or, the Cnt Ac-S
S-VOL can be used to provide remote backup of the BC P-VOL in case of an BC failure.
Figure 2 Shared Cnt Ac-S P-VOL with BC P-VOL
•
In the following figure, the Cnt Ac-S S-VOL also functions as an BC P-VOL. In this configuration,
BC provides another (or several more) backup copies of a Cnt Ac-S P-VOL.
When a BC P-VOL is shared with the Cnt Ac-S S-VOL, the write operation to the Cnt Ac-S
P-VOL takes a longer time than normal. This is especially true when the BC pair is in the
PSUS(SP)/PSUS status and is caused by the BC copying process.
Figure 3 Shared Cnt Ac-S S-VOL with BC P-VOL
•
In the following figure, the configurations shown in the previous two figures are combined.
Both the Cnt Ac-S P-VOL and S-VOL function as BC P-VOLs, providing multiple copies at the
local and remote sites.
Figure 4 Shared Cnt Ac-S P-VOL, S-VOL with multiple BC P-VOLs
42 Sharing Continuous Access Synchronous volumes