Software User Manual

Synchronous Consistency Groups
An XP Continuous Access Synchronous consistency group is a user-defined set of volume pairs. If
you specify a consistency group for XP Continuous Access Synchronous pairs, you can issue a
command for each group and can ensure the data consistency of pairs on each of the S-VOLs and
the R-VOLs in the same group.
XP Continuous Access Synchronous pairs or TrueCopy for Mainframe synchronous pairs can be
registered in an XP Continuous Access Synchronous consistency group. If an XP Continuous Access
Synchronous pair and a TrueCopy for Mainframe synchronous pair are registered in the same
group, you can ensure the data consistency between an XP Continuous Access Synchronous pair
and a TrueCopy for Mainframe synchronous pair on each of the S-VOLs and the R-VOLs in the
same group. If only XP Continuous Access Synchronous pairs or only TrueCopy for Mainframe
synchronous pairs are registered in the group, you can ensure the data consistency of the pairs
on each of S-VOLs or R-VOLs in each group. For more information on a TrueCopy for Mainframe
synchronous pair, see the Hitachi TrueCopy™ for Mainframe User Guide: HP XP24000 Disk Array,
HP XP20000 Disk Array.
If the split command (Pairsplit-r or YKSUSPND) is issued to the corresponding consistency group
and if the I/O processing on some volumes in the consistency group has not finished, the split
operation to the XP Continuous Access volume pair is executed after the I/O processing and the
data transfer to S-VOL have finished. Also, the split operation to the TrueCopy for Mainframe
volume pair is executed after the track processing of the volume that is in I/O processing and the
data transfer to R-VOL have finished.
Even if the suspend operation caused by system failure occurs to the pairs in a consistency group,
the suspend operation to the volume is executed similarly with ensuring the data consistency of the
pairs on each of the S-VOLs and the R-VOLs in the corresponding group.
You can ensure data consistency of the pairs on each of the S-VOLs and the R-VOLs in the same
DKC. XP Continuous Access allows you to configure up to 128 consistency groups (00-7F) for each
MCU.
For detailed information about synchronous consistency groups, see “XP Continuous Access
Synchronous Consistency Group Operations” (page 24).
XP Continuous Access synchronous pairs in the Synchronous consistency groups can be defined
and operated only by RAID Manager. TrueCopy for Mainframe synchronous pairs in the
Synchronous consistency groups can be defined and operated only by Business Continuity Manager.
For details, see the HP RAID Manager User Guide or the HP for Business Continuity Manager
Software User Guide.
To define or operate TrueCopy for Mainframe synchronous pairs in the Synchronous consistency
groups, install the TrueCopy for Mainframe software. An XP Continuous Access Synchronous
consistency group and a TrueCopy Open/MF consistency group described in the Hitachi TrueCopy
for Mainframe User Guide are the same. For further information on a TrueCopy Open/MF
consistency group, see the Hitachi TrueCopy™ for Mainframe User Guide: HP XP24000 Disk
Array, HP XP20000 Disk Array.
You must use the same consistency group number when XP Continuous Access Synchronous pairs
and TrueCopy for Mainframe Synchronous pairs are registered in the same XP Continuous Access
Synchronous consistency group. Therefore, you must decide beforehand the consistency group
number by both RAID Manager and Business Continuity Manager. Specify the unused consistency
group number. Before you start the operation, define the pair specifying the consistency group
number with RAID Manager and Copy Group Attributes (TC) window of Business Continuity
Manager. For further information about the Copy Group Attributes (TC) window, see the HP Business
Continuity Manager Software User Guide.
XP Continuous Access Components 13