HP StorageWorks XP Remote Web Console Software - Manual (Page 29)

secondary storage system issues a "read journal" command to the primary storage system, and then the
RCU target port at the primary storage system sends journal data to the secondary storage system in
response to the "read journal" command.
Any fibre-channel interface port of the XP disk array can be configured as an initiator port. The initiator
ports cannot communicate with the host processor channels. The host channel paths must be connected to
the fibre-channel interface port other than the initiator port.
NOTE:
Two or more initiator ports must be configured before you can add the secondary storage systems and
create the URz volume pairs.
The fibre-channel interface ports that are assigned for the RCU target ports can be connected to the
host channel paths via the fibre-channel switch.
See
Configuring Port Attributes on page 112Configuring Port Attributes for the information on configuring
host interface port.
URz Remote Console Software
XP disk array Storage Navigator Java applet program product includes URz for the XP disk array. The XP
disk array Storage Navigator software communicates with the SVP of each XP disk array via defined
TCP/IP connections. .
The Storage Navigator PC at the primary site must be attached to the primary subsystem. You should
also attach a Storage Navigator PC at the secondary site to all secondary subsystems. Having a
Storage Navigator PC at the secondary site enables you to change the URz parameter of the secondary
subsystem and access the URz secondary data volume (e.g. for the maintenance of media). If you need
to perform URz operations in the reverse direction from the secondary site to the primary site (e.g.,
disaster recovery), the XP disk array URz software simplifies and expedites this process.
NOTE:
If the XP Disk Array Storage Navigator remote console PC is not installed, please contact your HP
representative for information on URz configuration services.
Host I/O Time-Stamping Function
If you plan to establish URz journal groups, the I/O time-stamping function must be installed on the
host processor at the primary site. The I/O time-stamp, which is provided by MVS DFSMSdfp, is the
same time-stamp that is used by Compatible XRC pairs. The I/O time-stamping function should also be
installed on the host processor at the secondary site, so that time-stamps can be used when copying
data in the reverse direction.
If the system at the primary and/or secondary site consists of several CPU complexes, a SYSPLEX timer is
required to provide a common time reference for the I/O time-stamping function.
Error Reporting Communications (ERC)
Error reporting communications (ERC), which transfers information between host processors at the
primary and secondary sites, is a critical component of any disaster recovery effort. You can configure
ERC using channel-to-channel communications, NetView technology, or other interconnect technologies,
depending on your installation requirements and standards. Neither URz nor the URz remote console
software provides ERC between the primary and secondary sites.
When URz is used as a data migration tool, ERC is recommended but is not required. When URz is used
as a disaster recovery tool, ERC is required to ensure effective disaster recovery operations. When a URz
pair is suspended due to an error condition, the primary storage system generates sense information
Hitachi Universal Replicator for z/OS user guide for XP12000/XP10000 Disk Arrays and SVS 200 29