Lenovo THINKSERVER 3821 - Manual (Page 155)

2.5-inch hard disk drive backplane connectors
The following illustration shows the connectors on the 2.5-inch hard disk drive
backplane.
1 Hard disk drive connectors
2 Power connector
3 Signal connector
4 Configuration connector
Server power features
When the server is connected to an ac power source but is not turned on, the
operating system does not run, and all core logic except for the integrated
management module (IMM) is shut down; however, the server can respond to
requests from the IMM, such as a remote request to turn on the server. The
power-on LED flashes to indicate that the server is connected to ac power but not
turned on.
Turning on the server
Approximately 3 minutes after the server is connected to ac power, the
power-control button becomes active, and one or more fans might start running to
provide cooling while the server is connected to power. You can turn on the server
and start the operating system by pressing the power-control button.
The server can also be turned on in any of the following ways:
v If a power failure occurs while the server is turned on, the server will restart
automatically when power is restored.
v If your operating system supports the Wake on LAN ® feature, the Wake on LAN
feature can turn on the server.
For 32-bit operating systems only: Some memory is reserved for various
system resources and is unavailable to the operating system. The amount of
memory that is reserved for system resources depends on the operating system,
the configuration of the server, and the configured PCI options.
Chapter 6. Locating Server Controls and connectors 147