If you add more than 12 drives to an EMC AX4-5 Storage Array, you need to install the optional ExpansionTier / Expansion Enabler.
1 From the management host, open an Internet browser.
2 Enter the IP address of an SP in the storage system.
3 Log in to Navisphere Express with the username and password that you specified during the storage system initialization.
4 In the Navisphere Express navigation pane under System, click Software.
5 In the System Software screen, click Upgrade Software.
6 Insert the expansion pack media into the CD/DVD drive on the host from which you are running Navisphere Express.
7 Browse for the expansion tier enabler software file (.ena file), and click Upgrade