HP XP P9500 Storage - Manual (Page 26)

function should also be installed on the host processor at the secondary site, so that time stamps
can be used when copying data in the reverse direction.
If the system at the primary and/or secondary site consists of several CPU complexes, a SYSPLEX
timer is required to provide a common time reference for the I/O time stamping function.
Planning pair volumes
The following information can help you prepare volumes for configuration. Also, see system
requirements and specifications in
“Requirements and specifications” (page 16) for more information.
•
The emulation and capacity for the S-VOL must be the same as for the P-VOL
•
When the S-VOL is connected to the same host as the P-VOL, the S-VOL must be defined to
remain offline.
•
The following CU emulation types can be used for MCUs (primary systems) and RCUs
(secondary systems): 2105, 2107.
•
The CU emulation type 2105, or 2107 is required for SMS I/O time stamping of Cnt Ac-J Z
journals. When one of these CU emulation types is used, 3380 emulation type volumes must
not be used, though 3380-3 volumes may be used.
•
You can create a Cnt Ac-J Z pair using a Continuous Access Synchronous Z initial copy, which
takes less time. To do this, system option 474 must be set on the primary and secondary
systems. Also, a script is required to perform this operation. For more on system option 474
and how to do this operation, see
“System option modes ” (page 38) .
•
Cnt Ac-J Z supports the Virtual LVI feature, which allows you to configure custom LDEVs that
are smaller than standard LDEVs. When custom LDEVs are assigned to a Cnt Ac-J Z pair, the
S-VOL must have the same capacity as the P-VOL. For details about Virtual LVI feature, see
the HP P9000 Provisioning for Mainframe Systems User Guide.
•
Identify the volumes that will become the P-VOLs and S-VOLs.
•
You can create multiple pairs at the same time. Review the prerequisites and steps in “Creating
the initial copy ” (page 68) .
•
When you create a Cnt Ac-J Z pair, you will have the option to create only the relationship,
without copying data from P-VOL to S-VOL. You can use this option only when data in the two
volumes is identical.
•
When configuring the pair, best practice is to specify different serial numbers for the primary
and secondary systems.
Data and journal volume specifications
The following table shows maximum capacities and volume types that can be used for data volumes
and journal volumes.
Table 4 Data and journal volume specifications
Support specifications Type
Journal volume Data volume
Available Available Virtual LVI volume
Unavailable Available Cache Residency Z volume
2.377 GB 2.377 GB 3380-3 Maximum volume
capacity
0.964GB 0.964GB 3390-1
1.892GB 1.892GB 3390-2
2.838GB 2.838GB 3390-3
26 Planning volumes, P9500 systems