Hitachi Extended Remote Copy for Mainframe user guide (HITA738-96004, June 2008)

be written to the secondary volumes. Data is written to the secondary volumes in units of session in
the same order as it was written at the primary site, not in units of SC session.
SDM manages definitions of sessions and SC sessions. They are assigned session IDs and defined in
units of logical volume in the disk subsystem.
TSO commands
The following settings concerning XRC for Mainframe operations are defined by the TSO commands
issued to the disk subsystem from the host system.
• Start and end of the session
• Integration and withdrawal from the session
• Creation of utility volumes
• Creation and deletion of pair volumes
• Suspending of pairs
• Resuming suspended pairs
• Display of session status
• Display of utility volume status
• Display of pair status
• Recovery at the secondary site
NOTE:
For details on the TSO commands in XRC for Mainframe, see DFSMS Advanced Copy Services (Document
number: SC35-0428-02) published by IBM.
Configuration
XRC for Mainframe operations require hosts and storage systems at both primary and secondary sites,
and also a communications path between the subsystem at the primary site and the host running SDM
(typically at the secondary site). If the system at the primary site consists of several hosts, a SYSPLEX
timer is required in the primary host to provide a common time reference for the I/O time-stamping
function. The secondary host requires SDM, which is host software, for remote copy operations. The
XRC for Mainframe program product needs to be installed in the primary disk subsystem. The primary
site requires an XP Remote Web Console PC for setting options of the program product.
The following figure shows the connection configuration of channel extenders for XRC for Mainframe.
Overview of XRC for Mainframe Operations14