1. Check to see if any users are currently on the system. If they are, ask them to log off.
2. Once all of the users are logged off of the system, you may execute the 'shutdown' command.
The proper command for SCO UNIX systems is: shutdown 0
The proper command for IBM AIX systems is: shutdown -y -I0 -g0
3. Watch the computer system's main monitor. When the computer screen displays the message 'Safe to turn off computer', or 'System shutdown completed.', it will be safe for you to turn off the hardware.
4. Proceed to turn off the hardware. It is best to turn off the main computer unit first, then any auxiliary equipment, such as printers and tape drives. (This is not necessary, though).
Always follow the proper shutdown procedure! You can severely damage the filesystem if you do not shut down the machine properly.