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4.4 Changing Node Power States

Beginning with Torque 5.0.0, the pbsnodes -m command can modify the power state of nodes. Node cannot go from one low-power state to another low-power state. They must be brought up to the Running state and then moved to the new low-power state. The supported power states are:

State	Description
Running	Physical machine is actively working Power conservation is on a per-device basis Processor power consumption controlled by P-states
Standby	System appears off Processor halted (OS executes a "halt" instruction) Processor maintains CPU and system cache state RAM refreshed to maintain memory state Machine in low-power mode Requires interrupt to exit state Lowest-latency sleep state - has no effect on software
Suspend	System appears off Processor and support chipset have no power OS maintains CPU, system cache, and support chipset state in memory RAM in slow refresh Machine in lowest-power state Usually requires specific interrupt (keyboard, mouse) to exit state Third lowest-latency sleep state - system must restore power to processor and support chipset
Hibernate	System is off Physical machine state and memory saved to disk Requires restoration of power and machine state to exit state Second highest-latency sleep state - system performs faster boot using saved machine state and copy of memory
Shutdown	Equivalent to shutdown now command as root

In order to wake nodes and bring them up to a running state:

the nodes must support, and be configured to use, Wake-on-LAN (WOL).
the pbsnodes command must report the node's MAC address correctly.

To configure nodes to use Wake-on-LAN

Enable WOL in the BIOS for each node. If needed, contact your hardware manufacturer for details.

Use the ethtool command to determine what types of WOL packets your hardware supports. Torque uses the g packet. If the g packet is not listed, you cannot use WOL with Torque.

[root]# ethtool eth0
Settings for eth0:
	Supported ports: [ TP ]
	Supported link modes:   10baseT/Half 10baseT/Full 
	                        100baseT/Half 100baseT/Full 
	                        1000baseT/Full 
	Supported pause frame use: No
	Supports auto-negotiation: Yes
	Advertised link modes:  10baseT/Half 10baseT/Full 
	                        100baseT/Half 100baseT/Full 
	                        1000baseT/Full 
	Advertised pause frame use: No
	Advertised auto-negotiation: Yes
	Speed: 100Mb/s
	Duplex: Full
	Port: Twisted Pair
	PHYAD: 2
	Transceiver: internal
	Auto-negotiation: on
	MDI-X: off
	Supports Wake-on: pumbgWake-on: p
	Current message level: 0x00000007 (7)
			       drv probe link
	Link detected: yes

This Ethernet interface supports the g WOL packet, but is currently set to use the p packet.

If your Ethernet interface supports the g packet, but is configured for a different packet, use ethtool -s <interface> wol g to configure it to use g.

[root]# ethtool -s eth0 wol g
[root]# ethtool eth0
Settings for eth0:
	Supported ports: [ TP ]
	Supported link modes:   10baseT/Half 10baseT/Full 
	                        100baseT/Half 100baseT/Full 
	                        1000baseT/Full 
	Supported pause frame use: No
	Supports auto-negotiation: Yes
	Advertised link modes:  10baseT/Half 10baseT/Full 
	                        100baseT/Half 100baseT/Full 
	                        1000baseT/Full 
	Advertised pause frame use: No
	Advertised auto-negotiation: Yes
	Speed: 100Mb/s
	Duplex: Full
	Port: Twisted Pair
	PHYAD: 2
	Transceiver: internal
	Auto-negotiation: on
	MDI-X: off
	Supports Wake-on: pumbg
	Wake-on: g
	Current message level: 0x00000007 (7)
			       drv probe link
	Link detected: yes

Now the power state of your nodes can be modified and they can be woken up from power-saving states.