HP XP Racks - Manual (Page 13)

ESAM volumes that may be replicated. Review the Continuous Access Synchronous license installed
on your system to verify that it meets your requirements.
For example, when the license capacity for Continuous Access Synchronous is 10GB, the volume
capacity that can be used for ESAM is up to 10GB. When 2GB out of 10GB of license capacity
for Continuous Access Synchronous is used, the volume capacity that can be used for ESAM is up
to the remaining 8GB.
For information on licenses and the actions to take for expired licenses and exceeded capacity,
see the HP XP P9000 Remote Web Console User Guide.
Pair volume requirements
Data in the P-VOL on the primary storage system is copied to the S-VOL on the secondary storage
system. These two volumes are a pair.
The following are requirements for setting up P-VOLs and S-VOLs:
•
LDEVs for the P-VOL and S-VOL must be created and formatted before creating a pair.
•
The volumes must have identical block counts and capacity.
•
A P-VOL can be copied to only one S-VOL; and an S-VOL can be the copy of only one P-VOL.
•
Maximum number of pairs per storage system is 65,536.
The number of ESAM pairs that can be created depends on whether Continuous Access
Synchronous and/or Continuous Access Journal are used in the same storage system. ESAM,
Continuous Access Synchronous, and Continuous Access Journal share the same bitmap areas
used to manage differential data, which affects number of pairs. If one or both of these products
are used, the maximum number of the ESAM pairs allowed is than 65,536 and must be
calculated.
For instructions, see the topic on difference management in the HP XP P9000 Continuous
Access Synchronous User Guide.
•
The emulation type for P-VOLs and S-VOLs is OPEN-3, OPEN-8, OPEN-9, OPEN-E, OPEN-L,
and OPEN-V.
•
Multiple LU paths to each volume must be set using LUN Manager.
For instructions, see the HP XP P9000 Provisioning for Open Systems User Guide.
•
If you are storing data in an external volume or volumes, make sure the external volumes are
mapped to the primary or secondary storage system they support.
•
If you plan to create multiple pairs during the initial copy operation, observe the following:
All P-VOLs must be in the same primary storage system, or in mapped external systems. ◦
◦ All S-VOLs must be in the same secondary storage system, or in mapped external systems.
◦ You can specify the number of pairs to be created concurrently during initial copy
operations (1 to 16).
For more information about the System Option dialog box, see the topic on changing
option settings in the HP XP P9000 Continuous Access Synchronous User Guide.
◦ During the initial pair operation in RWC, you will select multiple P-VOLs on the primary
storage system for pairing. After selecting the P-VOL, only the P-VOL with the lowest LUN
appears in the subsequent Paircreate dialog box. To pair the other P-VOLs to the correct
S-VOLs, observe the following:
- In the Paircreate dialog box, you can select only one S-VOL. This should be the volume
to be paired with the P-VOL that is shown.
- S-VOLs for the remaining P-VOLs are assigned automatically by RWC, according to their
LUNs. If you are creating three P-VOLs, and you assign LUN001 as the S-VOL in the
Pair volume requirements 13