Hitachi TrueCopy for IBM z/OS User and Reference Guide (T5211-96001, June 2007)

2-4 About TrueCopy for z/OS Operations
Hitachi Universal Storage Platform V TrueCopy for IBM z/OS User’s Guide
USP V
TrueCopy for z/OS operations involve the main (primary) storage systems and
the remote (secondary) storage systems. This document covers TCz
operations in which the main storage system is a USP V and the remote
storage system is a USP V (or TagmaStore USP/NSC) storage system. The
main storage systems contain the TCz main volumes (M-VOLs), which contain
the original data and are online to the host(s). The remote storage systems
contain the TCz secondary volumes (R-VOLs), which are the synchronous or
asynchronous copies of the M-VOLs. TCz supports all CUs, volumes, and
physical hard drive options for the USP V. TCz supports RAID 1, RAID 5 and
RAID6 configurations. All USP Vs with TCz installed are compatible with the
IBM
®
PPRC host software function.
Note: The additional Shared Memory option is required for TrueCopy
operations.
Table 2-1 RAID Level Configurations of TrueCopy for z/OS
RAID Level of R-VOL RAID Level of M-VOL
RAID1 RAID5 RAID6
RAID1
Supported Supported Supported
RAID5
Supported Supported Supported
RAID6
Supported Supported Supported
To provide greater flexibility and to enable USP V to be tailored to unique
customer operating requirements, additional operational parameters, or
optional modes, are available for the USP V. At installation, the USP V modes
are set to their default values, so make sure to discuss these settings with
your Hitachi team. The USP V modes can only be changed by your Hitachi
representative. Table 2-2 shows the USP V modes related to TCz and PPRC
operations. Note: This mode information was current at the time of
publication of this document, but it may change. Please contact your Hitachi
representative for the latest USP V system option mode information.
Note: The USP V performing TCzA operations (main and remote) utilize
sidefiles in cache for storing the TCzA recordsets. Concurrent Copy (CC) also
utilizes cache sidefiles. Storage systems performing TCzA and/or CC must
have sufficient cache installed to handle the increased sidefile usage.
Insufficient cache can degrade storage system I/O performance and cause
command retry requests and state-change-pending (SCP) messages. See
Inflow Control of Recordsets
for further information on cache usage and
sidefile thresholds.