65 cu option settings preset list and pop-up menu – HP StorageWorks XP Remote Web Console Software User Manual
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118 Hitachi TrueCopy z/OS for HP XP12000/XP10000 and SVS 200 storage systems
3.
On the CU Option panel, change the CU options.
4.
Select the Set button to close the CU Option panel. The desired changes are now displayed in the
preset list.
Figure 65
CU Option settings preset list and pop-up menu
5.
Verify the desired changes in the preset list.
• To change settings, right-click the preset list, select Modify, make the desired changes, and close the
panel. The preset list displays the updated information.
• To omit the settings, right-click the preset list, and select Delete. The changes are cancelled.
• To cancel the change, right-click the reset list, and select Delete All. The changes are cancelled.
• To display error code, right-click the preset list, and select Error Detail. Error code is displayed at the
far right in the preset list.
6.
To apply the settings, select Apply (lower right of TrueCopy z/OS panel). To cancel the operation and
return the list to its original display, select Cancel.
Optimizing TrueCopy operations and disk array performance
All TC390 operations result in increased utilization of the disk array’s channel resources because of the
additional write (remote copy) operations to the secondary volumes. The TC390 update copy mode
(synchronous or asynchronous) determines exactly how the remote copy operations will impact disk array
performance as follows:
•
Synchronous copy mode (TC390 Synchronous) has an additional effect on disk array performance:
increased service and disconnect time for write I/Os to TC390 M-VOLs due to the delay between
channel-end and device-end. The length of this delay increases as the distance between the M-VOL and
R-VOL increases so that the longest delay occurs when the main and remote volumes are the maximum
distance apart.
•
Asynchronous copy mode (TC390A) eliminates all delays associated with TC390 Synchronous
operations while providing increased protections for write-dependent applications in the event of a
disaster. Write I/Os for TC390A M-VOLs are processed in the same way as writes for simplex volumes,
without any increase in service or disconnect time. The asynchronous R-VOL updates are performed
completely independent of all host I/O processes at the M-VOLs and there are no restrictions on
subsequent read/write operations to TC390A M-VOLs. The only performance concerns for TC390A are
ensuring that adequate cache resources are available for sidefiles that are used to store the recordsets
at both the MCUs and RCUs.
In addition to the TC390 update copy mode, several other factors can also affect XP12000/XP10000
performance. You can optimize both the TC390 operations and the I/O performance of the disk arrays by
analyzing workloads and addressing system-level conditions (for example, number of remote copy paths)
that can affect disk array performance. You can also control the impact of TC390 operations on disk array
performance by selecting the appropriate RCU options for each MCU (see ”
” on page 87) and the appropriate update copy mode (synchronous or asynchronous) and pair
options (see ”
Creating TrueCopy volume pairs (Add Pair)
” on page 125) for each TC390 pair. In addition,
you can upgrade the TC390 hardware components and/or adjust the configuration of the components to
improve disk array performance under a wide range of operating conditions. The following table lists some