Software Owner's manual

3-56 Chapter 3 Preparing for Universal Replicator z/OS Operations
Hitachi Universal Replicator for IBM /OS User’s Guide
Data transfer speed
between hosts and
the MCU
Data transfer speed of journal volumes
Data transfer speed
between the MCU and the RCU
Time
Normal status
Temporary increase in
data to be transferred
Data transfer
speed
Figure 3-31 Data Transfer Speed with URz (Data Transfer Speed of
Journal Volumes)
As illustrated in Figure 3-31, the data transfer speed (i.e., the speed for
reading and writing) of journal volumes in the master journal group must
exceed the amount of temporary increase in data to be transferred. If the data
transfer speed of journal volumes is below the amount of temporary increase
in data to be transferred, the journal data for the temporary increase in data
to be transferred will not be stored into journal volumes timely.
In
Figure 3-31, data transfer speed between the primary storage system and
the secondary storage system indicates transfer speed of journal data between
the primary storage system and the secondary storage system.
Planning RAID Group Configuration and Journal Group
Configuration
A RAID group can consist of physical volumes of different number of
revolutions, physical volumes of different capacity, and physical volumes of
different RAID configurations (e.g., RAID-1 and RAID-5). Data transfer speed
of RAID groups is affected by physical volumes and RAID configurations.