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$FreeBSD: stable/10/share/man/man5/devfs.5 232247 2012-02-28 07:35:07Z mm $
.Dd February 9, 2012 .Dt DEVFS 5 .Os .Sh NAME .Nm devfs .Nd device file system .Sh SYNOPSIS d -literal devfs /dev devfs rw 0 0 .Ed .Sh DESCRIPTION The device file system, or .Nm , provides access to kernel's device namespace in the global file system namespace. The conventional mount point is
a /dev .
p The file system includes several directories, links, symbolic links and devices, some of which can also be written. In a chroot'ed environment, .Nm can be used to create a new
a /dev mount point.
p The .Xr mknod 8 tool can be used to recover deleted device entries under .Nm .
p The .Xr fdescfs 5 filesystem is an alternate means for populating
a /dev/fd . The character devices that both .Nm and .Xr fdescfs 5 present in
a /dev/fd correspond to the open file descriptors of the process accessing the directory. .Nm only creates files for the standard file descriptors
a 0 ,
a 1 and
a 2 . .Xr fdescfs 5 creates files for all open descriptors.
p The options are as follows: l -tag -width indent t Fl o Ar options Use the specified mount .Ar options , as described in .Xr mount 8 . The following devfs file system-specific options are available: l -tag -width indent t Cm ruleset Ns No = Ns Ar ruleset Set ruleset number .Ar ruleset as the current ruleset for the mount-point and apply all its rules. If the ruleset number .Ar ruleset does not exist, an empty ruleset with the number .Ar ruleset is created. See .Xr devfs 8 for more information on working with devfs rulesets. .El .El .Sh FILES l -tag -width /dev/XXXX -compact t Pa /dev The normal .Nm mount point. .El .Sh EXAMPLES To mount a .Nm volume located on
p .Dl "mount -t devfs devfs /mychroot/dev" .Sh SEE ALSO .Xr fdescfs 5 , .Xr devfs 8 , .Xr mount 8 .Sh HISTORY The .Nm file system first appeared in .Fx 2.0 . It became the preferred method for accessing devices in .Fx 5.0 and the only method in .Fx 6.0 . The .Nm manual page first appeared in .Fx 2.2 . .Sh AUTHORS The .Nm manual page was written by .An Mike Pritchard Aq mpp@FreeBSD.org .