In the native environment, an arbitrary initial directory structure and file content can be built-in when the kernel is configured, but it will typically include at least the names above, to act as mount points. (See the discussion of the `root section' in conf(10.6).) The required file /osinit.dis (not present in the emulation environment) provides an executable Dis binary when read, and is the first program invoked when initialising the system. Other files needed for bootstrap might also reside in this device.

Its local name #/ can be used by programs outside the kernel, for instance to implement newns in newns(2).