Hot-Plug PCI Adapters
The function of hot-pluggable PCI adapters is to provide concurrent additions or removals of PCI adapters when the system is running. This function is explained in the following paragraphs.
In the chassis, the installed adapters inside the slots are protected by plastic separators, designed to prevent grounding and damage when adding or removing adapters. The hot-plug LEDs outside the chassis indicate if a adapter can be plugged in or removed from the system. These LEDs are also visible inside the chassis. Inside, the light from the LED is routed to the top of the plastic separators, using light pipes, which makes it very easy to locate the right slot. The hot-plug PCI adapters are secured with retainer clips on top of the slots; therefore, you do not need a screwdriver to add or remove a card and there is no screw to drop inside the chassis causing damage to the system.
The function of hot-plug is not only provided by the PCI slot, but also by the function of the adapter. Most adapters are hot-pluggable, but some are not. Be aware that some adapters must not be removed when the system is running, for example, the adapter with the operating system disks connected to it, or the adapter that provides the system console. Refer to the PCI Adapter Placement Reference Guide, SA38-0538 for further information.
To manage hot-plug PCI adapters, it is important to turn off slot power before adding, removing, or replacing the adapter, which is done by the operating system. There are three possibilities for managing hot-plug PCI slots in AIX:
•Command line:
•lsslot - List slots and their characteristics
•drslot - Dynamically reconfigures slots
•SMIT
•WebSM
When working with the commands and tools mentioned above, the hot-plug LEDs (see Figure 2) change their state. Table 1 shows the possible states of the hot-plug LEDs.
Table 1. Hot-Plug LED Indications
LED Indication | PCI Slot Status | Definition |
| | |
Off | Off | Slot power is off. It is safe to remove or |
| | replace adapters. |
| | |
On (not flashing) | On | Slot power is on. Do not remove or replace |
| | adapters. |
| | |
Flashing slowly (one | Identify | Indicates the slot has been identified by the |
flash per second) | | software; do not remove or replace adapters |
| | at this time. |
| | |
Flashing fast (six to | Action | Indicates the slot is ready for adding, |
eight flashes per | | removing, or replacing of adapters. |
second) | | |
| | |
To add a hot-plug PCI adapter use the drslot command to set the slot first into the Identify state (LED flashes slowly) to verity the right slot was selected. After pressing Enter, the LED changes its state to the Action state (LED flashes fast).
