IBM H SERIES RS/6000 - Manual (Page 23)

Stopping the System Unit
Attention: When using the shutdown procedure for your system, enter the correct
command before you stop the system unit. Failure to do so may result in the loss of
data. If you need information on the shutdown procedure for your operating system,
see your operating system documentation.
1. Before stopping the system unit, you must first perform a shutdown procedure of
the operating system to prevent the loss of data.
2. After you shut down the operating system, set the power switches of the
attached devices to Off.
3. The system unit is powered down by the shut down procedure.
Chapter 2. Using the System Unit 2-3