Updated: January 21, 2005
Applies To: Windows Server 2003, Windows Server 2003 R2, Windows Server 2003 with SP1, Windows Server 2003 with SP2
To use Emergency Management Services console redirection, Special Administration Console (SAC), or !Special Administration Console (!SAC), the operating system loader or kernel must be at least partially functioning. Therefore, when severe system problems cause a computer to completely stop responding, you must have a remote-management medium that can function entirely without the operating system. Service processors integrated onto system motherboards and Peripheral Component Interconnect (PCI) adapters provide such a medium.
Service processors can function this way because they operate independently of the processors in a computer. In addition, they use their own custom firmware and can even use a separate power supply to enhance reliability. You can communicate directly with a service processor through an out-of-band connection.
The management tools, features, and client interfaces provided by service processors differ from one manufacturer to another. They can range in complexity from a simple Telnet console to a rich Web-browser environment. You should evaluate the management features and troubleshooting tools provided by a service processor to ensure that they meet the needs of your organization.
Service processors can also provide support through media that are more complex than serial ports, such as Transmission Control Protocol/Internet Protocol (TCP/IP) on Ethernet. Service processors are typically integrated into system motherboards or add-in PCI adapters and function separately from the system's CPU.
Some service processors are also called Application Specific Integrated Circuits (ASICs). Depending on their original equipment manufacturer (OEM), service processors or ASICs can be implemented with many different types of out-of-band connection ports, including serial ports, Universal Serial Buses (USBs), modem connections, and RJ-45 Ethernet ports. The type of out-of-band connection you use determines which additional components are required to allow out-of-band access to your servers.
When selecting service processor hardware for use with Emergency Management Services, verify that the following functions are supported:
Turn on the computer
Turn off the computer
Access to Emergency Management Services
Field replaceable units (FRUs); for example, a hard disk
Internal hardware interface requirements
To provide complementary functionality, Emergency Management Services and service processors or ASICs must be available for remote management. The service processor must provide a pass-through connection between the operating system and the remote management client. With this functionality, you can use both Emergency Management Services and the service processor through a single connection medium.
The service processor must include an appropriate 16550 or 16450 Universal Asynchronous Receiver/Transmitter (UART) in its system input/output (I/O) as an internal hardware interface for Emergency Management Services. This UART hardware must be available to Emergency Management Services at all times, including when the operating system loader is running, when the operating system is fully loaded, and when a Stop error has occurred.
The UART interface must be fully described in the Serial Port Console Redirection (SPCR) table, or, in Itanium-based systems, through the Extensible Firmware Interface (EFI) console device path. For more information, see Enabling the SPCR table.
User interfaces for service processors
Original equipment manufacturers (OEMs) can define a range of user interfaces for their service processors. Serial ports and RJ-45 Ethernet interfaces are examples of two such user interfaces. Some interfaces might support more than one communication protocol; for example, Ethernet supports Telnet and Hypertext Transfer Protocol (HTTP), as well as others. Other interfaces use a single communication channel, such as a serial port.
With an interface that uses a serial port as its communication channel, you can use only one out-of-band management tool (Emergency Management Services or the service processor) at a time. Emergency Management Services and the service processor must share the interface reliably. Integration between Emergency Management Services and the service processor is especially important during the operating system's boot process because you are interacting with both Emergency Management Services and the service processor using the same serial interface. In addition, you are relying on both Emergency Management Services and the service processor to follow the same I/O conventions.
After a system restart, the service processor must release control of the serial port to Emergency Management Services. For this to occur, internal UART hardware must be available so that the service processor and Emergency Management Services can communicate with each other. If the service processor and Emergency Management Services both use VT100 conventions, communication will be successful, and the service processor can be invoked and exited. For more information about this, see VT-UTF8, VT100+, and VT100 conventions.
When the user interface is a multiple-channel interface, such as an RJ-45 Ethernet, the requirements for providing access to Emergency Management Services change. Access to Emergency Management Services must be available simultaneously with the out-of-band functionality provided by the service processor. The terminal interface that you use to manage the server should support VT100+ conventions.
Power switches or uninterruptible power supplies (UPS) with remote computer management capabilities
A power switch or uninterruptible power supply (UPS) provides control of the power that is supplied to the server. It can also provides basic remote-management capabilities, such as the ability to reset the system or turn it off. A power switch or UPS can also allow the serial communication between a management system and a server to pass through its port. That is, the port on the computer used for management can have a serial connection to an external serial port on the UPS, which can then have a serial connection to the server.
If you use a power switch or a UPS, it must provide unrestricted communication between the management computer and the Windows Server 2003 family out-of-band tools. A power switch or UPS can interrupt the out-of-band tools by using an escape sequence that is sent by the management computer. To use a power switch or UPS, the server must be configured to boot automatically when power is applied.
The following requirements must be met before you use a power switch or UPS with Emergency Management Services:
The UPS must be able to reset the system.
The UPS user interface must support the escape sequences and VT100+ conventions.
It might be preferable for the power switch or UPS to provide terminal concentrator functionality. For more information, see Terminal concentrators.
The following resources provide additional information about selecting hardware for Emergency Management Services: