NAME
vnd
—
vnode disk driver
SYNOPSIS
pseudo-device vnd
[count]
DESCRIPTION
The vnd
driver provides a disk-like
interface to a file. This is useful for a variety of applications, such as
building miniroot or floppy disk images.
This document assumes familiarity with how to generate kernels and how to properly configure disks and pseudo-devices in a kernel configuration file.
In order to compile in support for vnd
devices, a line similar to the following must be present in the kernel
configuration file:
pseudo-device vnd 4 # vnode disk driver
The count argument is how many
vnds
memory is allocated for at boot time. In this
example, no more than 4 vnds
may be configured.
There is a run-time utility that is used for configuring
vnds
. See
vnconfig(8) for more information.
IOCTL INTERFACE
The following ioctl(2) calls are defined in ⟨dev/vndioctl.h⟩:
VNDIOCSET
struct vnd_ioctl *- Associate the file vnd_file with a
vnd
pseudo device, optionally encrypted using the Blowfish cipher and the key specified in vnd_key of length vnd_keylen. The size of the configured device is returned in vnd_size.struct vnd_ioctl { char *vnd_file; off_t vnd_size; u_char *vnd_key; int vnd_keylen; };
VNDIOCCLR
struct vnd_ioctl *- Disassociate a
vnd
device. VNDIOCGET
struct vnd_user *- Get the associated file name, device, inode number, and unit number of a
vnd
device. If vnu_unit is -1, information on thevnd
device corresponding to the file descriptor passed to ioctl(2) will be returned. Otherwise, vnu_unit may contain the unit number of anothervnd
device. This allows for opening justvnd0
and querying all available devices.struct vnd_user { char vnufile[VNDNLEN]; int vnu_unit; dev_t vnu_dev; ino_t vnu_ino; };
Additionally, some
disklabel(8) related
ioctl(2) calls defined in
⟨sys/disklabel.h⟩ are available:
DIOCGDINFO
, DIOCSDINFO
, and
DIOCWDINFO
. They are documented in
sd(4).
FILES
- /dev/{,r}vnd*
vnd
device special files
SEE ALSO
ioctl(2), sd(4), disklabel(5), config(8), disklabel(8), fdisk(8), fsck(8), MAKEDEV(8), mount(8), newfs(8), vnconfig(8)