I/OBoards and Components 4-5
4
4.4 Hot-Plug Feature
Enterprise systems have extensive error detection mechanisms, and an
Automatic System Reconfiguration (ASR) feature that enables the system to be
rebooted with failed components (such as CPUs, memory,or I/O) disabled.
When an error is detected, the system can be reconfiguredso that the board
containing the failed components is placed in low power mode and is no
longer accessible.
Caution – The peripheral power supply provides the precharge voltages
required for hot-plug. Do not attempt hot-plug of a system component if the
power supply is missing or inoperative. Use prtdiag(1M) to determine the
status of the peripheral power supply.
Caution – If the message: NOTICE: Hot Plug not supported in this
system is displayed during boot, do NOT attempt hot-plug in this system or
damage to the hardware will occur.
The hot-plug feature enables you to insert a new board into a powered on
system, despite the system being “live,” or being supplied with electrical
power.When the hot-plug feature is used to add a board to a powered on
system, the system will not use the new board until the system is rebooted.
4.5 I/O Boards
Enterprise systems support two types of I/O boards: SBus and Graphics. See
Figure4-4 through Figure 4-7.
The SBus I/O board includes two SYSIO ASICs that provide two SBuses:
•One for two plug-in SBus cards and two fiber interfaces
•One for one plug-in SBus card and the on-board devices (10/100Mbyte TPE
and Single-ended Fast/Wide SCSI)
Note – SBus connector slots 1 and 2 on the SBus I/O boardcan accommodate a
double-wide SBus card.