Out-of-band management
Encyclopedia
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 server
s 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 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 access to BIOS settings, or the reinstallation of the operating system and cannot be used to fix problems that prevent the system from booting. (New version of RealVNC demonstrated at the Intel Developers Conference has shown out-of-band management)
Both in-band and out-of-band management is usually done through the network connection, but an out-of-band management card can use a physically separated network connector if preferred. A remote management card usually has an at least partially independent power supply, and can power the main machine on and off through the network.
or RAM
clocking can be also be adjusted as the management card needs no hard drives or main memory to operate.
As management via a serial port has traditionally been important on servers, a complete remote management system also allows one 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 a memory card where an administrator may keep server-related information independently from the main hard drive.
The remote system can be accessed either through SSH Command line interface, a specialized client software or through various web browser based solutions. Client software is usually optimized to manage multiple systems easily.
There are also various down-scaled 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.
Computing
Computing is usually defined as the activity of using and improving computer hardware and software. It is the computer-specific part of information technology...
, 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
System administrator
A system administrator, IT systems administrator, systems administrator, or sysadmin is a person employed to maintain and operate a computer system and/or network...
to monitor and manage server
Server (computing)
In the context of client-server architecture, a server is a computer program running to serve the requests of other programs, the "clients". Thus, the "server" performs some computational task on behalf of "clients"...
s and other network equipment by remote control regardless of whether the machine is powered on.
By contrast, in-band management like VNC
Virtual Network Computing
In computing, Virtual Network Computing is a graphical desktop sharing system that uses the RFB protocol to remotely control another computer...
or SSH
Secure Shell
Secure Shell is a network protocol for secure data communication, remote shell services or command execution and other secure network services between two networked computers that it connects via a secure channel over an insecure network: a server and a client...
is based on 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 access to BIOS settings, or the reinstallation of the operating system and cannot be used to fix problems that prevent the system from booting. (New version of RealVNC demonstrated at the Intel Developers Conference has shown out-of-band management)
Both in-band and out-of-band management is usually done through the network connection, but an out-of-band management card can use a physically separated network connector if preferred. A remote management card usually has an at least partially independent power supply, and can power the main machine on and off through the network.
Capabilities
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 one to perform 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 RAIDRAID
RAID is a storage technology that combines multiple disk drive components into a logical unit...
or RAM
Random-access memory
Random access memory is a form of computer data storage. Today, it takes the form of integrated circuits that allow stored data to be accessed in any order with a worst case performance of constant time. Strictly speaking, modern types of DRAM are therefore not random access, as data is read in...
clocking can be also be adjusted as the management card needs no hard drives or main memory to operate.
As management via a serial port has traditionally been important on servers, a complete remote management system also allows one to talk with the server through this port (SOL
Serial over LAN
Serial Over LAN is a mechanism that enables the input and output of the serial port of a managed system to be redirected over IP.On some managed systems, notably blade server systems, the serial ports on the managed computers are not normally connected to a traditional serial port socket...
console).
As sending monitor output through the network is bandwidth intensive, cards like MegaRAC
MegaRAC
The MegaRAC from American Megatrends is a successful product line of Service Processors providing complete out-of-band, or Lights-out remote management of computer systems. MegaRAC Service Processors come in various formats - PCI cards, embedded modules, software-only...
use built-in video compression. Devices like Dell DRAC also have a slot for a memory card where an administrator may keep server-related information independently from the main hard drive.
The remote system can be accessed either through SSH Command line interface, a specialized client software or through various web browser based solutions. Client software is usually optimized to manage multiple systems easily.
There are also various down-scaled versions, up till devices that only allow remote reboot by power cycling
Power cycling
Power cycling is the act of turning a piece of equipment, usually a computer, off and then on again. Reasons for power cycling include having an electronic device reinitialize its configuration or recover from an unresponsive state of its mission critical functionality, such as in a crash or hang...
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.
See also
- Intelligent Platform Management InterfaceIntelligent Platform Management InterfaceThe Intelligent Platform Management Interface is a standardizedcomputer system interface used by system administrators to manage a computer system and monitor its operation....
- a server out-of-band management standard - Intel Active Management TechnologyIntel Active Management TechnologyIntel Active Management Technology is hardware-based technology for remotely managing and securing PCs out-of-band.Currently, Intel AMT is available in desktop PCs with Intel Core 2 processor with Intel vPro technology and available in laptop PCs with Centrino or Centrino 2 platform with vPro...
- an Intel out-of-band management protocol - Desktop and mobile Architecture for System HardwareDesktop and mobile Architecture for System HardwareDASH is a DMTF standard on requirements for implementing the Desktop and Mobile Architecture for System Hardware....
- an out-of-band management standard - HP Integrated Lights-Out (a HP out-of-band management product)
- Dell DRAC (a DELL out-of-band management product)
- IBM Remote Supervisor Adapter (an IBM out-of-band management product)