This section provides an overview of hot plug management, specifically PCI Hot Plug Support for PCI adapters. For information about using the PCI hot plug features and procedures for unconfiguring, adding, removing, and replacing adapters, see Managing Hot Plug Connectors in AIX 5L Version 5.1 System Management Guide: Operating System and Devices.
For information about the commands you can use to display information about PCI hot plug slots and to add, replace, or remove PCI hot plug adapters, see:
PCI Hot Plug Management consists of user interfaces that allow you to manage hot plug connectors, also known as dynamic reconfiguration connectors, or slots. A connector defines the type of slot, for example, PCI. A slot is a unique identifier. Dynamic reconfiguration is the ability of the system to adapt to changes in the hardware and firmware configuration while it is still running.
PCI Hot Plug Support for PCI Adapters is a specific subset of the dynamic reconfiguration function that provides the capability of adding, removing, and replacing PCI adapter cards while the host system is running and without interrupting other adapters in the system. You can also display information about PCI hot plug slots.
Different hot plug connector types require different operations to perform various hot plug management functions. For example, adding a SCSI device requires different operations than when you add a PCI adapter card.
Note: Although PCI hot plug management provides the capability of adding, removing, and replacing PCI adapters without powering off the system or restarting the operating system, not all devices in hot plug slots can be managed in this fashion. For example, the hard disk that makes up the rootvg volume group or the I/O controller to which it is attached cannot be removed or replaced without powering off the system because it is necessary for running the operating system.
Some adapters cannot be hot plugged and should not be removed while the system unit is running. To determine whether an adapter can be hot plugged, refer to the list of supported PCI adapters in the PCI Adapter Placement Reference, which is shipped with system units that support PCI hot plug.
You can insert a new PCI adapter into an available PCI slot while the operating system is running. This can be another adapter of the same type currently installed or a different type of PCI adapter. New resources are made available to the operating system and applications without having to restart the operating system. Some reasons for adding an adapter might include:
For steps on how to add a PCI hot plug adapter, see Adding a PCI Hot Plug Adapter in the AIX 5L Version 5.1 System Management Guide: Operating System and Devices.
You can remove a PCI hot plug adapter from its I/O drawer or enclosure without shutting down the operating system or turning off the system power. Removing an adapter makes the resources provided by the adapter unavailable to the operating system and applications. Before you remove the adapter, you must ensure that any resources using the adapter are not in use when you remove it. Some reasons for removing an adapter might include:
For steps on how to remove a PCI hot plug adapter, see Removing or Replacing a PCI Hot Plug Adapter in the AIX 5L Version 5.1 System Management Guide: Operating System and Devices.
You can exchange a defective or failing PCI hot plug adapter with another of the same type without shutting down the operating system or turning off the system power. Because the adapter is of the same type, the existing device driver is able to support the replacement adapter. The replace function retains the configuration information about the replaced adapter and compares this information to the card that replaced it. Device configuration and configuration information about devices below the adapter are utilized in configuring the replacement device.
Some reasons for replacing an adapter might include:
For steps on how to replace a PCI hot plug adapter, see Removing or Replacing a PCI Hot Plug Adapter in the AIX 5L Version 5.1 System Management Guide: Operating System and Devices.
Before you can remove or replace a hot plug device, it must be unconfigured. The associated device driver must free any system resources that it has allocated for the device. This includes unpinning and freeing memory, undefining interrupt and EPOW handlers, releasing DMA and timer resources, and any other required steps. The driver must also ensure that interrupts, bus memory, and bus I/O are disabled on the device.
It is expected that the system administrator will perform the following tasks before and after the removal process:
Note: If you add an adapter using a PCI hot plug replace or add operation, it and its child devices may not be available for specification as a boot device using the bootlist command. You may have to restart the machine to make all potential boot devices known to the operating system.
In some cases, the system administrator may also perform the following tasks:
Attention: Before you attempt to remove or insert PCI hot plug adapters, refer to the PCI Adapter Placement Reference, (shipped with system units that support hot plug), to determine whether your adapter can be hot-swapped. Refer to your system unit documentation for instructions for installing or removing adapters.
The remove and replace operations fail unless the device connected to the identified slot has been unconfigured and is in the defined state. You can do this with the rmdev command. Before placing the adapter in the defined state, close all applications that are using the adapter, otherwise, the command will be unsuccessful.
This section provides an overview of the process for unconfiguring PCI communications adapters. This includes Ethernet, Token-ring, FDDI, and ATM adapters. For procedural information, see Unconfiguring Communications Adapters in the AIX 5L Version 5.1 System Management Guide: Operating System and Devices.
If your application is using TCP/IP protocol, you must remove the TCP/IP interface for the adapter from the network interface list before you can place the adapter in the defined state. Use the netstat command to determine whether your adapter is configured for TCP/IP and to check the active network interfaces on your adapter.
An Ethernet adapter can have two interfaces: Standard Ethernet (enX) or IEEE 802.3 (etX). X is the same number in the entX adapter name. Only one of these interfaces can be using TCP/IP at a time. For example, Ethernet adapter ent0 can have en0 and et0 interfaces.
A Token ring adapter can have only one interface: Token-ring (trX). X is the same number in the tokX adapter name. For example, Token-ring adapter tok0 has a tr0 interface.
An ATM adapter can have only one atm interface: ATM (atX). X is the same number in the atmX adapter name. For example, ATM adapter atm0 has an at0 interface. However, ATM adapters can have multiple emulated clients running over a single adapter.
The ifconfig command removes an interface from the network. The rmdev command unconfigures the PCI device while retaining its device definition in the Customized Devices Object Class. Once the adapter is in the defined state, you can use the drslot command to remove the adapter.