HP XP P9500 Storage - Manual (Page 29)

Using an existing CTG
You can assign new pairs or existing pairs to an existing consistency group.
Procedure 4 To assign new pairs to an existing consistency group
1. Add Cnt Ac-S and Cnt Ac-S Z pair information to the existing configuration definition file B,
which consists of pairs in multiple XP P9500s.
2. Copy and create RAID Manager configuration definition file C.
3. Perform the paircreate operation for Cnt Ac-S and Cnt Ac-S Z pairs and register them to
configuration definition file C.
Procedure 5 To assign existing pairs to an existing consistency group
1. Create RAID Manager configuration definition file A with which to use RAID Manager for pair
operations.
2. Perform the pairsplit operation on the Cnt Ac-S and Cnt Ac-S Z pairs that you want to register
in the existing CTG with multiple systems. Do this using configuration definition file A.
3. Perform the pairresync operation on the Cnt Ac-S and Cnt Ac-S Z pairs, without designating
a consistency group. Do this using configuration definition file A.
4. Perform the pairsplit operation on the Cnt Ac-S and Cnt Ac-S Z pairs again, using configuration
definition file A.
5. Perform the pairsplit operation to the existing configuration definition file B, which consists of
the pairs in the multiple primary and secondary system configuration.
6. Add Cnt Ac-S and Cnt Ac-S Z pair information to existing configuration definition file B.
7. Delete then re-create the Cnt Ac-S and Cnt Ac-S Z pairs, registering them in configuration
definition file C.
Split and suspension behaviors for pairs in a CTG
When the pairs in a consistency group receive updates while in the process of being split or
suspended, or when they are about to be split or suspended, S-VOL data consistency is managed
as follows:
•
If I/O processing is in progress on Cnt Ac-S or Cnt Ac-S Z pairs in the same consistency group,
and the split or suspend operation begins, the I/O processing completes first, then the
split/suspend operation is run.
The following figure shows that I/O processing completes first; then the pair split operation
for the Cnt Ac-S pair on Volume B completes.
The following figure shows data in track 2 being copied to the R-VOL, and the data in track 3
becomes differential data. In this case, track 2 is used for I/O processing to the volume in the
consistency group when the split command is issued to the pair.
Consistency group planning 29