Compaq ProLiant 6500 Compaq ProLiant 7000 Server Technology - Page 12

ECG078/0698 TECHNOLOGY BRIEF (cont.) ... The server also has one primary hot-plug fan and one redundant hot-plug fan for the I/O board in the upper section of the server (Figure 7). Should the primary fan fail, the redundant fan will start automatically. Redundant Hot-Plug Fan Primary Hot-Plug Fan Failed OK ( A m b(AFemarilb)eedr)( G(GrOereKeenn)) LEDs Figure 7: Hot-plug fans for the I/O section. The server fan control logic operates independent of the system processor and operating system (OS). Regardless of the OS that is running or its condition, the fan control logic and the server temperature monitoring circuitry work together to cool the server effectively. The fans have two speeds: normal and high. Under typical circumstances, the normal fan speed is sufficient to cool up to four processors, eighteen hard disk drives, and ten I/O expansion boards. As a precaution against increases in ambient air or localized internal temperatures, Compaq has established three thermal trip points, as shown in Figure 8. When the first thermal trip point is reached, the fans adjust automatically to high speed to increase cooling. Users can select whether to enable the following server response to the second thermal trip point. If the internal air temperature exceeds the second trip point, the OS initiates a controlled shutdown of the server. Simultaneously, a warning message is sent to the IMD and Compaq Insight Manager. The server restarts automatically when it has cooled sufficiently. Finally, in the unlikely event server temperature continues to rise, a third trip point shuts down the power supplies to protect critical components from overheating. The server restarts automatically when it has cooled sufficiently. 12