Lights out management
Lights-out management (LOM) is the ability for a system administrator to monitor and manage servers by remote control. A complete LOM system consists of a hardware component called the LOM module and a program that facilitates the continuous monitoring of variables such as microprocessor temperature and utilization. The program also allows for such remote operations as rebooting, shutdown, troubleshooting, alarm setting, fan-speed control, and operating system reinstallation.
Servicing and managing computer servers in a remote data center can require the physical presence of a system administrator. For example, the loading or removal of media, or direct interaction with the server through a console and keyboard. Such access requirements depend on a system administrator being co-located with the data center, an additional business expense.
A single LOM system can be used with more than one server without the need for on-site staff at any of the server locations. Communication between the controller and the remote servers can be done through an independent dial-up connection. More commonly nowadays, the LOM modules are connected by serial links to a separate management host; or the LOM module accepts telnet connections over an Ethernet connection. Either way, the LOM can then be remotely accessed over the Internet (through SSH to the management host, and/or a VPN). The LOM module keeps a record of all the operations (known as the event log), allowing the administrator to instantly check any or all of several hundred systems.
An example of a LOM system is Sun Advanced Lights Out Management (ALOM), which comes standard on newer Sun servers (Sun Fire V210/240/250/440, Netra 240/440.) Netra had a similar older product called LOM on their Netras, and also Remote System Control (RSC) on Sun VSP servers.