Shutdown

SSH the server with your userid + password

Execute the command

The root password is also needed (see image below)

login as: ibmsys1
[email protected]'s password:
Last login: Fri Aug  5 00:19:37 2016 from 9.78.130.50
[ibmsys1@kvm1awb ~]$ shutdown -h now
==== AUTHENTICATING FOR org.freedesktop.login1.power-off ===
Authentication is required for powering off the system.
Authenticating as: root
Password:
==== AUTHENTICATION COMPLETE ===

On the HMC, the Operating System Messages screen will show up the message:

and the LPAR status change from Operating to Not Operating:

Now, you can deactivate the LPAR to free the resources.

If you want to bring the systems up again, click on Recovery > Load task.