Modifying Parameters And Deleting Consistency Groups; Asynchronous Option Settings Parameter List - HP StorageWorks XP12000 User Manual

When channel-extenders are used for Continuous Access XP Async, the offloading timer should be set
to 35 seconds or less to avoid affecting host I/O performance.
• I/O Delay Start: Threshold (0-70%), which is maximum amount of cache for starting inflow
control for the asynchronous copy. When amount of cache used for async recordsets reaches the
specified threshold, the MCU controls the cache inflow.
• I/O Delay Increase: Threshold (0-70%), which is maximum amount of cache for starting to
strengthen control over inflow for the asynchronous copy. When amount of cache used for async
recordsets reaches the specified threshold, the MCU controls cache inflow.
NOTE:
Specify a value not exceeding the I/O Delay Increase for the I/O Delay Start. Specify a value not
exceeding the Pending Update Data Rate for the I/O Delay Increase. If sidefile threshold is set
between 0 to 30%, influence to the I/O delay is kept low.
HP recommends that you change the I/O Delay Start and I/O Delay Increase when all Continuous
Access XP asynchronous pairs are suspended, or host I/O and sidefiles do not exist. If you do not want to
control inflow into a sidefile, specify the value same as the Pending Update Data Rate for the I/O Delay
Start and I/O Delay Increase, and specify 0 second for the Offloading Timer.
1. From the Consistency Group list, right-click, and click Async Option. The Async Option pane appears.
NOTE:
You do not have to select a consistency group on the list.
2.
In the Async Option pane, select parameters.
3. Click Set to set parameters. The list changes to the Asynchronous Option Settings Parameter list.
NOTE:
After being set, options can be modified and canceled (see
deleting consistency
4.
Click Apply on the Continuous Access XP main pane to apply option settings to the disk array.
When the Async Option pane closes, the list changes to the Asynchronous Option Settings Parameter list.
Figure 45 Asynchronous Option Settings Parameter list
• Pending Rate: Sidefile allocation in %. Indicates sidefile threshold, which is maximum amount of
cache used for storing Continuous Access XP asynchronous recordsets (sidefiles).
• Offloading: Offloading timer in seconds. Indicates that the MCU waits to send a Continuous
Access XP Async recordset to the RCU.
• Delay Start: Maximum amount of cache for starting inflow control for the asynchronous copy.
• Delay Increase: Maximum amount of cache for starting to strengthen control over inflow for the
asynchronous copy.

Modifying parameters and deleting consistency groups

After the Consistency Group (CT Group) and Asynchronous Option operations, parameters can be
modified individually, and consistency groups set by the operation can be deleted.
92
Continuous Access XP for the Array
groups).
Modifying parameters and