You can use the LUN properties dialog box in System Manager to change the name, description, size, space reservation setting, or the mapped initiator hosts of a LUN.
When you resize a LUN, you have to perform the steps on the host side that are recommended for the host type and the application that is using the LUN.
Click Storage > LUNs.
In the LUN Management tab, select the LUN that you want to edit from the list of LUNs, and click Edit.
Make the required changes.
Click Save and Close.