Changing from 3990 to 2105 or 2107 emulation – HP StorageWorks XP Remote Web Console Software User Manual
Page 137

Table 47 Optimizing TrueCopy for Mainframe Operations and HP disk array Performance
Recommendation(s)
Description
Condition
Spread write intensive data across
several volumes to minimize queuing.
Write-intensive workloads, such as
SPOOL volumes and database logging
Write-intensive workloads
volumes, can have a significant impact
on storage system I/O response times.
Spread workloads with large write
block sizes across several volumes.
Workloads with large write block
sizes, such as DB2 deferred writes,
can impact performance.
Large block size
Spread the workload across several
storage systems to utilize additional
channels.
The demand on the MCU's host
channels can affect performance.
High host channel demand
Avoid performing restore operations to
volumes which belong to TrueCopy for
TrueCopy for Mainframe operations
can have a negative impact on
Sequential write operations
Mainframe pairs. Instead, restore data
workloads with a high percentage of
to a scratch volume and then establish
the TrueCopy for Mainframe pair.
sequential write operations, such as
batch processing operations (for
example, dump/restore, sort
operations).
Consider increasing the cache size of
the TrueCopy for Mainframe storage
Large cache size improves read hit
performance, which allows more
Cache size
systems to handle TrueCopy for
storage system resources to be
Mainframe Asynchronous, Compatible
devoted to write operations. The
XRC, and CC sidefile operations and
resulting performance improvement
to improve overall storage system
can offset some or all of the
performance. For best results, the cache
performance loss due to the TrueCopy
and NVS capacity of the main and
for Mainframe remote copy
operations.
remote storage systems should be the
TrueCopy for Mainframe
Asynchronous, Compatible XRC, and
same (for TrueCopy for Mainframe
Asynchronous the RCU sidefile
requirements are 2x that of the MCU)
Concurrent Copy (CC) require
to enable the remote site to function
adequately during disaster recovery.
additional cache for sidefile data.
Insufficient cache resources can result
in command retries, SCP notifications,
and puncture conditions.
Distribute TrueCopy for Mainframe
remote copy operations among several
The performance of the RCUs directly
affects the performance of the MCUs.
RCU capacity
remote storage systems to avoid
overloading any one RCU.
If an RCU becomes overloaded with
heavy update activity, MCU and
system performance can also be
degraded.
Make sure to install an adequate
number of remote copy connection
An inadequate number of remote copy
connection paths may decrease
Remote copy connection paths
paths between the main and remote
storage system performance.
storage systems. This is especially
Performing TrueCopy for Mainframe
important for storage systems which
contain both M-VOLs and R-VOLs.
Synchronous operations over long
distances can also degrade storage
system performance. TrueCopy for
Mainframe Asynchronous is
recommended for long distances.
Changing from 3990 to 2105 or 2107 Emulation
TrueCopy for Mainframe supports 3990-6, 3990-6E, 2105, and 2107 controller emulation types
for the HP disk array MCU and RCU. The 3990-6, 3990-6E, 2105 or 2107emulation is required
for SMS I/O time-stamping of TrueCopy for Mainframe Asynchronous recordsets. The 2105 and
2107 emulation type is required for Compatible PAV operations.
Configuring and Maintaining Your TrueCopy for Mainframe Environment
137