Com port initialized to BMC use when AC power first applied - Servers

Resolving The Problem

RETAIN tip: H192223

When the system is first connected to AC power, the COM port switch is initialized to Baseboard Management Controller (BMC) private use only.

When the system is powered on without changing this initial default setting, the COM port is not available under the operating system.

The system may be any of the following IBM servers:

• System x3250 M2, type 4190, any model
• System x3250 M2, type 4191, any model
• System x3250 M2, type 4194, any model

This tip is not option specific.

This tip is not software specific.

To get the COM port to function under the operating system after the system is first connected to AC power, the COM port switch must be set properly under the POST Configuration/Setup Utility.

For reference, the BMC on System x3250 M2 (Types 4190, 4191, 4194) requires standby power from the system board.

When the AC power is first applied to the system, the BMC will start initialization. As a result, the COM port switch is initialized to BMC-private use only as a default setting.

Under this setting, the BMC has total control over the COM port for Serial Over Lan, IPMI over Serial, and remote console redirect features.

However, once the system boots into the operating system, the COM port is hidden from the operating system. The user will not be able to use this COM port as a normal COM port purpose, i.e., the serial mouse will not work.

To be able to use this COM port as a normal COM port under the operating system, the user is required to change the setting under POST Configuration/Setup Utility by pressing F1 during POST. Once entering the POST Configuration / Setup Utility, go to Advanced Setup and BMC Settings. Under this page, set System-BMC Serial Port sharing to Enabled and BMC Serial Port Access Mode to Shared. Be sure to Save Settings before exiting.