Accessing Devices

System administrators need to know how to specify device names when using commands to manage disks, file systems, and other devices. In most cases, system administrators use logical device names to represent devices connected to the system. Both logical and physical device names are represented on the system by logical and physical device files.

How Device Information Is Created

When a system is booted for the first time, a device hierarchy is created to represent all the devices connected to the system. The kernel uses the device hierarchy information to associate drivers with their appropriate devices, and provides a set of pointers to the drivers that perform specific operations. See the OpenBoot 3.x Command Reference Manual for more information on device hierarchy.

Device Naming Conventions

Devices are referenced in three ways in the Solaris environment.

• Physical device name - Represents the full device pathname in the device information hierarchy. Physical device names are displayed by using the following commands:

  • dmesg

  • format

  • sysdef

  • prtconf

  Physical device files are found in the /devices directory.

• Instance name - Represents the kernel's abbreviation name for every possible device on the system. For example, sd0 and sd1 represent the instance names of two disk devices. Instance names are mapped in the /etc/path_to_inst file and are displayed by using the following commands:

  • dmesg

  • sysdef

  • prtconf

• Logical device name - Used by system administrators with most file system commands to refer to devices. See Table 26-1 for a list of file commands that use logical device names. Logical device files in the /dev directory are symbolically linked to physical device files in the /devices directory.