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DEVFS(5) FreeBSD File Formats Manual DEVFS(5)
NAME
devfs - device file system
SYNOPSIS
devfs /dev devfs rw 0 0
DESCRIPTION
The device file system, or devfs, provides access to kernel's device
namespace in the global file system namespace. The conventional mount
point is /dev.
The file system includes several directories, links, symbolic links and
devices, some of which can also be written. In a chroot'ed environment,
devfs(8) can be used to create a new /dev mount point.
The mknod(8) tool can be used to recover deleted device entries under
devfs.
The fdescfs(5) filesystem is an alternate means for populating /dev/fd.
The character devices that both devfs and fdescfs(5) present in /dev/fd
correspond to the open file descriptors of the process accessing the
directory. devfs only creates files for the standard file descriptors 0,
1 and 2. fdescfs(5) creates files for all open descriptors.
The options are as follows:
-o options
Use the specified mount options, as described in mount(8). The
following devfs file system-specific options are available:
ruleset=ruleset
Set ruleset number ruleset as the current ruleset for the
mount-point and apply all its rules. If the ruleset
number ruleset does not exist, an empty ruleset with the
number ruleset is created. See devfs(8) for more
information on working with devfs rulesets.
FILES
/dev The normal devfs mount point.
EXAMPLES
To mount a devfs volume located on /mychroot/dev:
mount -t devfs devfs /mychroot/dev
SEE ALSO
fdescfs(5), devfs(8), mount(8), make_dev(9)
HISTORY
The devfs file system first appeared in FreeBSD 2.0. It became the
preferred method for accessing devices in FreeBSD 5.0 and the only method
in FreeBSD 6.0. The devfs manual page first appeared in FreeBSD 2.2.
AUTHORS
The devfs manual page was written by Mike Pritchard <mpp@FreeBSD.org>.
FreeBSD 14.2-RELEASE June 30, 2022 FreeBSD 14.2-RELEASE