Re: Creating /dev/dk* nodes so as to be persistent

[mlelstv%serpens.de@localhost (Michael van Elst)]

mueller6724%bellsouth.net@localhost ("Thomas Mueller") writes:

>I can run
>MAKEDEV dk15 dk16 dk17 ...
>but these don't survive for the next boot.

With a standard installation, /dev is just a directory on
the root filesystem and device nodes do not disappear
by a reboot.

If you boot from a disk where /dev hasn't been installed
correctly (in particular, if it lacks a console entry),
then a temporary RAM disk is created with only standard
devices. This is a mechanism that is used during the
installation, but not on a properly installed system.


>Linux and FreeBSD now allocate device nodes dynamically, but I remember the 
>old days when FreeBSD and Linux preconfigured device nodes statically as 
>NetBSD and OpenBSD still do.

Linux and FreeBSD use a special-purpose filesystem for /dev.

There hasn't been any decision about using this approach for NetBSD.
Some people prefer a special-purpose filesystem, some believe that
a simple RAM disk that is automatically populated is sufficient.

So you find two mechanisms in -current:

- ptyfs, which is something like a devfs, but only for ptys.
- devpubd, a userland daemon that could manage device nodes in
  a classical /dev directory. So far it has hooks to
  - create missing device nodes when a device is attached.
  - create and delete symbolic links to device nodes to access wedges
    by name.