Changing the MP
unit assigned to an LDEV
Use this procedure to change the MP unit assigned to an LDEV.
Before you begin
-
Changes to the MP unit ID of an LDEV should be made during off-peak hours when the I/O load is as low as possible. Before and after changes are made, it is recommended that the cache write-pending rate (%) for all CLPRs is lower than 50%. Do not change the MP unit ID when the I/O load is high -- for example: during initial copy of ShadowImage, TrueCopy, global-active device, or Universal Replicator.
-
When you change the MP unit ID of an LDEV, you should use Performance Monitor before and after the change to check the load status of devices. Do not change several LDEV MP unit IDs during a short period of time. As a guideline, you can change 10% or less of the total number or the full workload of LDEV MP unit IDs assigned to the same MP unit ID at the same time.
-
After you change the MP unit for an LDEV, wait more than 30 minutes before you try to change the ID again for the same LDEV.
Procedure
Click Storage Systems, and then expand the Storage Systems tree.
Click Logical Devices.
In the Logical Devices window, select the LDEV ID of the LDEV that has the MP unit you want to change.
Click More Actions, and then select Assign MP Unit.
In the Assign MP Unit window, specify the MP unit in MP Unit.
Click Finish.
The Confirm window appears.In the Task Name text box, type a unique name for the task or accept the default.
You can enter up to 32 ASCII characters and symbols, with the exception of: \ / : , ; * ? " < > |. The value "date-window name" is entered by default.Click Apply.
If Go to tasks window for status is selected, the Tasks window appears.
