6.16. Power Management

Cobbler allows for linking your power management systems with cobbler, making it very easy to make changes to your systems when you want to reinstall them, or just use it to remember what the power management settings for all of your systems are. For instance, you can just change what profile they should run and flip their power states to begin the reinstall!

6.16.1. What’s Supported

All of the following modes are supported. Most all of them use the fence scripts internally so you will want fence installed. This is part of the ‘cman’ package for some distributions, though it’s fence-agents in Fedora 11 and later (which cobbler has as a dependency on that OS for newer versions).

  • bullpap

  • wti

  • apc_snmp

  • ether_wake

  • ipmilan

  • drac

  • ipmitool

  • ilo

  • rsa

  • lpar

  • bladecenter

  • and many more…

6.16.2. Example of Set Up

You have a WTI powerbar. Define that system foo is a part of that powerbar on plug 7

cobbler system edit --name foo --power-type=wti --power-address=foo-mgmt.example.org --power-user Administrator --power-pass PASSWORD --power-id 7

You have a DRAC based blade:

cobbler system edit --name blade7 --power-type=drac --power-address=blade-mgmt.example.org --power-user Administrator --power-pass=PASSWORD --power-id blade7

You have an IPMI based system:

cobbler system edit --name foo --power-type=ipmi --power-address=foo-mgmt.example.org --power-user Administrator --power-pass=PASSWORD

You have a IBM HMC managed system:

cobbler system edit --name 9115-505 --power-type=lpar --power-address=ibm-hmc.example.org --power-user hscroot --power-pass=PASSWORD --power-id system:partition


The –power-id option is used to indicate both the managed system name and a logical partition name. Since an IBM HMC is responsible for managing more than one system, you must supply the managed system name and logical partition name separated by a colon (‘:’) in the –power-id command-line option.

You have an IBM Bladecenter:

cobbler system edit --name blade-06 --power-type=bladecenter --power-address=blademm.example.org --power-user USERID --power-pass=PASSW0RD --power-id 6


The *--power-id* option is used to specify what slot your blade is connected.

6.16.3. Data Entry

Tip: to make life easier, you can use cobbler find + xargs [CommandLineSearch](Command Line Search) to batch populate the settings for lots of systems.

6.16.4. Defaults

If --power-user and --power-pass are left blank, the values of default_power_user and default_power_pass will be loaded from cobblerd’s environment at the time of usage.

--power-type also has a default value in our settings, initially set to “ipmilanplus”.

6.16.5. Using the Power Management Features

Assigning A System To Be Installed To A New Profile

obbler system edit --name=foo --netboot-enabled=1 --profile=install-this-profile-name-instead

Powering Off A System

cobbler system poweroff --name=foo

Powering On A System

cobbler system poweron --name=foo

Rebooting A System (if netboot-enabled is turned on, it will now reinstall to the new profile – assuming PXE is working)

cobbler system reboot --name=foo

Since not all power management systems support reboot, this is a “power off, sleep for 1 second, and power on” operation.

6.16.6. Implementation

The individual command syntaxes are generated from Cheetah templates in /etc/cobbler/power in case you need to modify the commands or add additional options. You can also add new power types if you like if you are using Cobbler 2.0 and later, just by making new files in that directory.

6.16.7. Important: Security Implications

Storing the power control usernames and passwords in Cobbler means that information is essentially public (this data is available via XMLRPC without access control), therefore you will want to control what machines have network access to contact the power management devices if you use this feature (such as /only/ the cobbler machine, and then control who has local access to the cobbler machine). Also do not reuse important passwords for your power management devices. If this concerns you, you can still use this feature, just don’t store the username/password in Cobbler for your power management devices.

If you are not going to to store power control passwords in Cobbler, leave the username and password fields blank.

Cobbler will first try to source them from it’s environment using the COBBLER_POWER_USER and COBBLER_POWER_PASS variables.

This may also be too insecure for some, so in this case, don’t set these, and supply --power-user and --power-pass when running commands like cobbler system poweron and cobbler system poweroff. The values used on the command line are always used, regardless of the value stored in Cobbler or the environment, if so provided.

cobbler system poweron --name=foo --power-user=X --power-pass=Y

Be advised of current limitations in storing passwords, make your choices accordingly and in relation to the ease-of-use that you need, and secure your networks appropriately.