HP StorageWorks XP24000 Continuous Access Software User and Reference Guide, v01 (T5278-96002, June 2007)

for async recordsets reaches the specifie d value of the threshold, the MCU controls the c ash inflow. It
follows that the delay of I/O time of MCU occurs.
The I/O Delay Increase option allows you to specify the threshold (30-70%), which is the maximum
amount
of cache for star ting to strengthen control over the inflow for the asynchronous copy. When the
amount of cache that is used for async recordsets reaches the specified value of the threshold, the MCU
controls the cash inflow. It follows that the delay of I/O time of MCU increases.
Note: Specifyavaluenot exceeding the valueofI/O DelayIncreasefor thevalue of I/ODelay Start.
Specify a value not exceeding the value of Pending Update Data Rate for the value of I/O Delay
Increase. If the sidefile threshold is set between 0 to 30%, the influence to the I/O delay is kept low.
Note: HP recommends that you change the values of I/O D elay Start and I/O Delay Increase when all
asynchronous pairs of Continuous Access are suspended, or neither the host I/O nor sidefiles exist. If you
do not
want to control the inflow into a sidefile, specify the same value as the Pending Update Data Rate
for both values of I/O Delay Start and I/O Delay Increase, an d 0 seconds for the Offloading Timer.
To set the async options:
1. Click the Asynchronous O peration tab. You do not need to select anything in the tree.
2. Right-click the CT group list (you do not need to select anything), and click Async O ptio n to open
the
Async Option dialog box (see Figure 32 on page 84). The async op tions can only be
modified when no Continuous Access Asynchronous pairs or groups exist in the c onnected CU
(P-VOLs or S-VOLs).
3. O n the Async Option dialog box, select the desired parameters. For further information on the
asynchronous copy options, see above and “In flow Control of Recordsets” on page 24.
4. Click Set to close the Async Option dialog box . (Click Cancel to cancel the async option
operation.) The preview list displays the requested async option operation.
5. Verify the requested operation displayed in the preview list.
To change the async option operation, select the operation from the preview list, right-click, and
click Modify. To remove the operation, select it from the preview list, right-click, and click Delete.
To cancel all operations, select all the operations in the preview list, right-click, and click the
Delete command, or click the Cancel button.
6. To apply the settings, click the Apply button.
Adding Consistency Groups
The Add CT Group dialog box (see Figure 33 on page 85) allows you to add consistency groups and
select the options for the new groups. To open the Add CT Group dialog box, click the Asynchronous
Opera
tion
tab, click Display All or Not Used in the tree, select the group(s) to be added, right-click the
group(s), click CT Group O peration,and click Add CT Group.
Figure 33 Add CT Group Dialog Box
MCU-RCU Path: Indicates the path t ype (fibre) for the remote copy connections. Currently, you cannot
change the path type.
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