Configuring Host Power On

The XenServer Host Power On feature allows you to manually turn a remote host (server) on and off. To use this feature, you need to carry out the following steps:

  1. Ensure that the server supports remote power control. That is, the server has Wake on LAN functionality, a DRAC card, or it is using a custom script.
  2. Enable the Host Power On functionality. To perform this procedure for DRAC processors, you need the credentials for the processor, which are set in its firmware.

After Host Power On has been configured on a server, you can power the server on from XenCenter. Select the server and then, on the Server menu, click Power On.

If you have installed and configured Workload Balancing, you can also configure XenServer to turn hosts on and off as VMs are consolidated or brought back online. This feature is known as Power Management.

Prerequisites for Host Power On

To enable the Host Power On feature, the host server must have one of the following power control solutions:

  • A network card that supports Wake On LAN (WOL).
  • Dell Remote Access Controller (DRAC). To use XenServer with DRAC, follow these steps:
    1. Install the Dell supplemental pack.
    2. Install the RACADM command-line utility on the host server with the remote access controller.
    3. Enable DRAC and its interface. RACADM is often included in the DRAC management software. For more information, see Dell’s DRAC documentation.
  • A custom power-on script based on the Management API that enables you to turn the power on and off through XenServer. For DRAC, you can use the secrets feature (by specifying the key power_on_password_secret ) to help you store your password more securely. For more information, see Hosts and Resource Pools.

To enable or disable Host Power On

You can enable Host Power On for an individual server by using the server Properties window, or on multiple servers by using the pool Properties window.

  1. Select the server or pool and open its Properties dialog box: on the Server or Pool menu, click Properties.
  2. Click the Power On tab and under Power On mode, select the option you want:
    • Disabled Select this option to disable the Host Power On feature.
    • Wake on LAN (WOL) To use this option, the host must have a Wake on LAN-enabled network card.
    • Dell Remote Access Controller (DRAC) To use this option, the Dell supplemental pack must be installed on the host server to get DRAC support. For more information, see Dell’s DRAC documentation.
    • Custom power-on script You can use a custom Python Linux script to turn on the power on the XenServer host from a remote location. For information about creating the script, including a list of supported key/value pairs, see the Hosts and resource pools.
  3. If you selected Dell DRAC, enter the following information:
    • IP Address The IP address you specified configured to communicate with the power-control card. Alternatively, you can enter the domain name for the network interface where DRAC is configured.
    • User name This is the DRAC user name that is associated with the management processor. You might have changed this value from its factory default settings.
    • Password This is the password associated with that user name.
  4. If you selected Custom power-on script, enter the file name and path to the custom script you created. Under Configuration options, enter the key/value pairs you want to use to configure the script. Move between fields by clicking or tabbing.

    You do not need to specify the .py extension when you specify the file name of the custom script.

  5. Click OK to save your configuration changes and close the Properties window.

After configuration, you can configure and run the Workload Balancing Automation and Host Power On features.

Configuring Host Power On