Lights Out management

Out of Band Management
http://en.wikipedia.org/wiki/Out-of-band_management

In computing, out-of-band management (sometimes called lights-out management or LOM) involves the use of a dedicated management channel for device maintenance. It allows a system administrator to monitor and manage servers and other network equipment by remote control regardless of whether the machine is powered on.

By contrast, in-band management like VNC or SSH is based on the software that must be installed on the remote system being managed and only works after the operating system has been booted. This solution may be cheaper but it does not allow to access BIOS settings, reinstall operating system and cannot be used to fix problems that prevent system from booting.

Both in and out band management is usually done through the network connection, but out band management card can use a physically separated network connector if preferred. Remote management card usually has at least partially independent power supply and can power the main machine on and off through the network.

A complete remote management system allows remote reboot, shutdown, powering on, hardware sensor monitoring (fan speed, power voltages, chassis intrusion, etc), broadcasts video output to remote terminal and receives input from the remote keyboard and mouse. It also can access local media like DVD drive from the remote machine. If necessary, this allows to perform the remote installation of the operating system. Remote management can be used to adjust BIOS settings that may not be accessible after the operating system has already booted. Settings of hardware RAID or RAM clocking can be also be adjusted as the management card needs no hard drives or main memory to operate.

As serial port has traditionally been important on servers, a complete remote management also allows to talk with the server through this port (SOL console).

As sending monitor output through the network is bandwidth intensive, cards like MegaRAC use built-in video compression. Devices like Dell DRAC also have a slot for memory card where administrator may keep server-related information independently from the main hard drive.

The remote system can be accessed either through the specialized client software or through various web browser based solutions. Client software is usually optimized to manage multiple systems easily.

There are also various downscaled versions, up till devices that only allow remote reboot by power cycling the server. This helps if the operating system hangs but only needs reboot to recover.

Remote management can be enabled on many computers (not necessarily servers) by adding the remote management card (while some cards only support limited list of motherboards). Newer server motherboards often have the built-in remote management and need no separate management card.

Intelligent Platform Management Interface (IPMI)
Intelligent Platform Management Interface (a server out-of-band management standard protocol)

Vendor Implementations

 * Intel Active Management Technology (Intel's out-of-band management technology)
 * HP's Guardian Service Processor (HP's out-of-band management implementation for older HP 9000 servers)
 * HP Integrated Lights-Out (iLO) (HP's out-of-band management implementation for x86 and newer Integrity servers)
 * Dell DRAC/iDRAC (DELL's out-of-band management implementation)
 * IBM Remote Supervisor Adapter or Integrated Management Module (IBM's out-of-band management implementation)

HP iLO
Integrated Lights-Out (abbreviated as iLO), an embedded server management technology exclusive to Hewlett-Packard; similar in functionality to the Lights out management (LOM) technology of other vendors

HP Integrated Lights-Out - Wikipedia, the free encyclopedia - http://en.wikipedia.org/wiki/HP_Integrated_Lights-Out

See HP iLO

Dell DRAC
In computing, the Dell Remote Access Controller or DRAC, an interface card from Dell Inc, provides out-of-band management facilities. The controller has its own processor, memory, network connection, and access to the system bus. Key features include power management, virtual media access and remote console capabilities, all available through a supported web browser or command line interface. This gives system administrators the ability to configure a machine as if they were sitting at the local console (terminal).