HP StorageWorks XP Remote Web Console Software - Manual (Page 50)

To operate the URz software, PC for the XP Remote Web Console is required. For further information
on HP XP Remote Web Console operations, see the HP StorageWorks XP Remote Web Console
user guide for XP12000/XP10000 Disk Arrays and SVS 200, or contact your HP account team.
Planning of Journal Volumes
This section contains an explanation of how to plan your Journal Volumes.
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“Why Planning is Necessary” (page 50)
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“What to Consider for Planning” (page 50)
•
“How to do Planning” (page 50)
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“Contributing Factors for Data Transfer Speed between Storage Systems” (page 53)
Why Planning is Necessary
Data transfer speed for journal groups is affected by specifications of journal volumes that the
journal groups use. Therefore, you need to think about specifications of journal volumes to be used
by journal volumes, in order to achieve the data transfer speed that you want.
What to Consider for Planning
This section explains what you need to consider when deciding on journal volume specifications.
The following factors affect the speed for writing to and reading from journal volumes, particularly
when a temporary communication path failure occurs between the primary storage system and the
secondary storage system, or when the amount of data transferred from hosts to the primary storage
system is increasing:
•
RAID configuration of the RAID groups that will contain journal volumes
•
Types of physical volumes in the RAID groups that will contain journal volumes
•
Frequency of access to non-journal volumes in the RAID groups that will contain journal volumes
•
Data transfer speed required for the non-journal volumes mentioned above
•
Disk usage rate for RAID groups
The following factor affects the time during which data transfer with hosts can continue without
being influenced by a temporary communication path failure between the primary storage system
and the secondary storage system, or without being influenced by an increase in the data to be
transferred from hosts to the primary storage system:
•
Capacity of journal volumes
How to do Planning
Data Transfer Speeds for Journal Volumes
Figure 12 (page 51) illustrates how the data transfer speed (that is, the amount of data to be
transferred per unit of time) will change as time elapses, citing different types of data transfer speed
with URz. Data transfer speed between hosts and the primary storage system goes through two
phases; in one phase the data transfer speed remains almost unchanged, and in another phase
the data transfer speed increases temporarily.
50 Requirements and Restrictions for Universal Replicator z/OS Operations