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devfs(5) [freebsd man page]

DEVFS(5)						      BSD File Formats Manual							  DEVFS(5)

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 environ- ment, devfs 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) 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 <>. BSD
February 9, 2012 BSD

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DEVFS.CONF(5)						      BSD File Formats Manual						     DEVFS.CONF(5)

devfs.conf -- boot-time devfs configuration information DESCRIPTION
The devfs.conf file provides an easy way to set ownership and permissions, or create links for devices available at boot. It does not work for devices plugged in and out after the system is up and running, e.g. USB devices. See devfs.rules(5) for setting owner- ship and permissions for all device nodes, and devd.conf(5) for actions to be taken when devices are attached or detached. Lines starting with a hash sign ('#') and empty lines are ignored. The lines that specify devfs.conf rules consist of three parameters sepa- rated by whitespace: action The action to take for the device. The action names are only significant to the first unique character. devname The name of the device created by devfs(5). arg The argument of the action. The actions currently supported are: link This action creates a symbolic link named arg that points to devname, the name of the device created by devfs(5). own This action changes the ownership of devname. The arg parameter must be in the form of an owner:group pair, in the same format used by chown(8). perm This action changes the permissions of devname. The arg parameter must be a mode as explained in chmod(1). FILES
/etc/devfs.conf /usr/share/examples/etc/devfs.conf EXAMPLES
To create a /dev/cdrom link that points to the first SCSI(4) CD-ROM, the following may be added to devfs.conf: link cd0 cdrom Similarly, to link /dev/cdrom to the first ATAPI CD-ROM device, the following action may be used: link acd0 cdrom To set the owner of a device, the own action may be specified: own cd0 root:cdrom To set the permissions of a device, a perm action should be used: perm cd0 0660 SEE ALSO
chmod(1), devd.conf(5), devfs(5), devfs.rules(5), chown(8) AUTHORS
This manual page was written by Roland Smith <>. BSD
May 17, 2005 BSD
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