NAME

mkdisk − create disk device descriptor files

USAGE

/etc/mkdisk [−S | −W | −F] [−c number] [−d number] [−l number] [−r] devname

DESCRIPTION

The mkdisk command creates the block and character special device files that describe the disk devices attached to a node. 

DOMAIN/IX nodes currently support three types of disk device. The conventional name for each type of disk is as follows:

Winchester disks wn

Storage modules sm

Floppy disks fl

By convention, the names assigned to block disk device files on a DOMAIN/IX system include the disk type name as listed above, concatenated with the drive number and a character denoting the logical volume number.  Thus, for example, logical volume 1 of drive 0 of a storage module disk would conventionally be named /dev/sm0a. In this case, the prefix “dev” is the name of the directory where all “special files” normally live; the “sm” indicates that this is a storage module disk; the “0” is the drive number, and the “a” indicates that this is logical volume 1 (since logical volumes on a physical drive are numbered from 1). Similarly, /dev/fl1b would name logical volume 2 of floppy disk drive 1. 

The UNIX operating system makes a distinction between block and “raw” (character) devices.  Each disk has a block device interface that makes the device byte-addressable.  There are also “raw” devices available.  Some UNIX systems place restrictions on the use of raw devices (for example, on some systems, raw devices must be read or written 512 bytes at a time).  No such restrictions currently exist on DOMAIN/IX raw devices; in general, raw and block devices can be used interchangeably on DOMAIN/IX. 

Typically, there will be both a raw device descriptor file and a block device descriptor file for each disk on a DOMAIN/IX system.  The names of the raw device descriptor file and the block device descriptor file are related: if the block device is named /dev/xx0a, the raw device will be named /dev/rxx0a, with the “r” representing “raw”.

The mkdisk program creates block and character disk device descriptor files.  If run with no options, mkdisk tries to figure out the disk type and unit numbers from the disk descriptor file name you supply, using the naming conventions described above. 

OPTIONS

You may use mkdisk to create disk descriptor files whose names do not follow the conventions described above, by supplying the needed information in options.  If an option is explicitly supplied, it overrides the information mkdisk deduces from the filename. 

−S The disk is a storage module. 

−W The disk is a Winchester. 

−F The disk is a floppy disk. 

−c number Controller number. 

−d number Drive number. 

−l number Logical volume number. 

−r The disk is raw. 

EXAMPLE

/etc/mkdisk /dev/wn1c

creates a block device descriptor file for logical volume 3 of drive 1 on the Winchester disk. 

DIAGNOSTICS

The diagnostics are intended to be self-explanatory. 

RELATED INFORMATION

mount (1) umount (1)