Power Control
=============

You can control the power to your slice using the power buttons in the panel.

.. Note::
   It is recommended that you powerdown and reboot your slices directly, 
   using their respective commands over SSH:

   * For poweroff, using ``poweroff`` or ``shutdown`` commands
   * For reboot, the ``reboot`` commmand.

   Details as to why are described below.


Power Off
---------

Upon clicking the :guilabel:`Power Off` button, the system will issue an ACPI ("soft")
power down request.  It will wait **90 seconds** for the slice to report it has 
cleanly shutdown.  If it does not, the system will issue a **hard shutdown**, which is 
the equivalent of pulling the power plug.  

This is why we recommend you issue the commands over SSH instead: there is no time limit 
in that case, so you can wait as long as you need (and possibly watch the shutdown over 
the :doc:`console` as well, by opening it prior to clicking :guilabel:`Power Off`).

But the panel button is still required for cases where a slice might be unreachable, 
e.g. a slice is hard locked.  Or, someone with panel access but not direct SSH access 
needs to power cycle, etc.


Power On
--------

Upon clicking the :guilabel:`Power On` button, the system will issue an ACPI poweron
request and wait for the slice to report success.  

.. Note::
   The status reflected on the panel is what is reported by the slice; the system only 
   knows if your slice is in a running state or not.  But your slice might still be 
   unreachable for some other reason, such as SSH did not start or a rogue firewall 
   rule, etc. 

   The :doc:`console` is often useful in these cases.


Reboot
------

Upon clicking the :guilabel:`Reboot` button, the system will issue an ACPI reboot 
request and wait for the slice to report success.  This is different than :guilabel:`Power Off`
in that there is no time limit; from the perspective of the host the slice remains in 
a running state.  In cases where a slice hard locks during reboot, you can use the 
:guilabel:`Power Off` button to force a **hard shutdown**, which is the equivalent of
pulling the power plug.