The devfs file system manages the /devices directory, which is the name space of all devices on the system. This directory represents the physical devices that consists of actual bus and device addresses.
The dev file system manages the /dev directory, which is the name space of logical device names.
By default, the devfsadm command attempts to load every driver in the system and attach to all possible device instances. Then, devfsadm creates the device files in the /devices directory and the logical links in the /dev directory. The devfsadm command also maintains the path_to_inst instance database.
Updates to the /dev and /devices directories in response to dynamic reconfiguration events or file system accesses are handled by devfsadmd, the daemon version of the devfsadm command. This daemon is started by the service management facility when a system is booted.
Because the devfsadmd daemon automatically detects device configuration changes generated by any reconfiguration event, there is no need to run this command interactively.
For more information, see the following references: