After our EqualLogic PS6000 decided to go into a NetBSD Kernel Panic (crash) while performing a firmware update from version 5.1.1 to 5.1.2 using the Group Manager GUI, resulting in a firmware mismatch on our controllers, As advised by EqualLogic Tech support I performed another update to FW 5.1.2 using the CLI, with success.
Using the CLI has its advantages, altough the process is a little more involved, ie copying the firmware to the array member using FTP then SHH to the member to execute the update, you do get to see what happens during a firmware update in more detail.
Here is the process of performing a Firmware update using the CLI.
Firstly download the firmware from EqualLogic Support https://support.equallogic.com
Lets update the firmware.