DEV(7FS) File Systems DEV(7FS)

Device name file system

The dev filesystem manages the name spaces of devices in the operating system. The global zone's instance of the dev filesystem is mounted during boot on /dev. This filesystem is colloqiually called ‘sdev’ as a way to distinguish it from the devfs(7FS) filesystem mounted at /devices.

A subdirectory under /dev may have unique operational semantics. Most of the common device names under /dev are created automatically by devfsadm(1M) Others, such as /dev/pts, /dev/net, and /dev/zvol are dynamic and reflect the operational state of the system. You can manually generate device names for newly attached hardware by invoking devfsadm(1M) or implicitly, by indirectly causing a lookup or readdir operation in the filesystem to occur. For example, you can discover a disk that was attached when the system was powered down (and generate a name for that device) by invoking format(1M).

In a non-global zone, the dev filesystem is also mounted at /dev; however, it is generally speaking read-only. Unlike in the global zone, a privileged user in a non-global zone cannot create directories or files, directories, or other objects within the filesystem.

Mount point for the dev filesystem in the global zone and non-global zones.

devfsadm(1M), format(1M), devfs(7FS)

The global /dev instance cannot be unmounted.
November 29, 2021 OmniOS