How can I check the memory usage of the SonicWall appliance using the Command Line Interface (CLI)?

SonicWall UTM appliances provide support for command line interface (CLI) commands to monitor and manage the device. Memory usage can be seen in real time monitor from the GUI only when the device is running in diagnostic mode or a debug firmware build. 

1. Log in to SonicWall management from CLI. To see how to initiate a management session in CLI, please refer How to login to the appliance using the Command Line Interface (CLI). 
2. If the firmware on device is 5.8.1.x, type the command ‘show memory’ without quotes.
   
3. If the firmware on device is 5.9.0.x or 6.1.x.x or 6.2.x.x, type the command ‘diag show memory’ without quotes.