HP XP for Compatible Extended Remote Copy Software Licenses - Manual (Page 11)

1 Overview of Compatible XRC
This chapter summarizes the IBM Compatible XRC process and reviews the copy features that can be
used in combination with Compatible XRC in mainframe systems.
• About Compatible Replication for IBM XRC (Compatible XRC)
• Reviewing Other Supported Copy Features
About Compatible Replication for IBM™ XRC (Compatible
XRC)
Compatible Replication for IBM™ XRC (henceforth referred to as Compatible XRC) in the XP24000
Disk Array and HP XP20000 Disk Array storage system is an asynchronous remote copy feature used
for data backup in the event of a disaster.
Compatible XRC is used in mainframe systems and is functionally compatible with IBM Extended
Remote Copy (XRC), an IBM host software feature. Compatible XRC is provided as a program product
and is compatible with System Data Mover (SDM) in DFSMS (Data Facility Storage Management
Subsystem), which is common to the XRC environment. Compatible XRC operations are performed in
the same manner as XRC operations. XRC TSO commands are issued from the host system to the
XP24000/XP20000 Disk Array storage system.
Compatible XRC temporarily stores the data written by the host at the primary site as a sidefile to the
cache. Upon request of the host at the secondary site, Compatible XRC asynchronously transfers the
sidefile for data backup to a secondary site.
Since compatible XRC is an asynchronous remote copy feature, response time to the primary site does
not depend on the distance between the primary and secondary sites. Therefore, a long distance
connection can be used between these sites. By using a common time stamp provided by the Sysplex
timer, you can guarantee that data written at the secondary site is in the same order as at the primary
site.
In Compatible XRC operations, a group of volumes is processed as one session. The order of writes
at the secondary site is guaranteed for each session. You can register 4,096 sessions in one storage
system and Compatible XRC enables you to have a large-scale remote copy system involving multiple
hosts.
The Compatible XRC program product must be installed in the storage system at the primary site. For
the installation procedure, please refer to the HP StorageWorks XP24000/XP20000 Remote Web
Console User's Guide.
Reviewing Other Supported Copy Features
XP24000/XP20000 Disk Arrays support the following copy features that can be used in combination
with HP Compatible XRC in mainframe systems:
• Hitachi TrueCopy™ for Mainframe
• Hitachi ShadowImage™ for Mainframe
• XP for Flashcopy™ Mirroring
XP24000/XP20000 for Compatible Extended Remote Copy (XRC) Software User's Guide 11