System Administration Guide, Volume 1

What's New in Device Management?

This section provides information about new Solaris 8 features related to device management.

SCSI and PCI Hot-Plugging

The cfgadm command is updated in this release to provide SCSI and PCI hot-plugging for supported SCSI and PCI controllers on SPARC based and IA based systems.

Hot plugging is the ability to physically add, remove, or replace system components while the system is running. Dynamic reconfiguration, available on certain SPARC servers, allows a service provider to remove and replace hot-pluggable system I/O boards in a running system, eliminating the time lost in rebooting. Also, if a replacement board is not immediately available, the system administrator can use dynamic reconfiguration to shut down a failing board while allowing the system to continue operation.

See your SPARC hardware manufacturer's documentation for information about whether dynamic reconfiguration is supported on your system. See the Solaris 8 (Intel Platform Edition) Hardware Compatibility List to verify whether your PCI controller supports hot-plugging.

Chapter 25, Configuring Devices describes how to use the cfgadm command to hot-plug SCSI or PCI controllers.

Improved Device Configuration (devfsadm)

The devfsadm command manages the special device files in the /dev and /devices directories. By default, devfsadm attempts to load every driver in the system and attach to all possible device instances. Then it creates the device files in the /devices directory and the logical links in the /dev directory. In addition to managing the /dev and /devices directories, devfsadm also maintains the path_to_inst(4) instance database.

In previous Solaris releases, device configuration was handled by drvconfig, which managed the physical device entries in the /devices directory, and five link generators, devlinks, disks, tapes, ports, and audlinks, which managed the logical device entries in the /dev directory.

These utilities were not aware of hot-pluggable devices nor were they flexible enough for devices with multiple instances. For compatibility purposes, drvconfig and the other link generators are symbolic links to the devfsadm utility. See Chapter 25, Configuring Devices for information about hot-pluggable devices.

Both reconfiguration boot processing and updating the /dev and /devices directories in response to dynamic reconfiguration events is handled by devfsadmd, the daemon version of the devfsadm command. This daemon is started from the /etc/rc* scripts when a system is booted.

Since devfsadmd automatically detects device configuration changes generated by any reconfiguration event, there is no need to run this command interactively.

See devfsadm(1M) for more information.