format Command

Purpose

Formats either diskettes or read/write optical media disks.

Syntax

format [ -d Device ] [ -f ] [ -l ]

Description

Attention: Formatting a diskette or read/write optical disk destroys any existing data on it.

The format command formats diskettes in the diskette drive specified by the Device parameter. The format command determines the device type, which can be one of the following:

5.25 inch low-density diskette (360 KB) containing 40x2 tracks, each with 9 sectors
5.25 inch high-capacity diskette (1.2 MB) containing 80x2 tracks, each with 15 sectors
3.5 inch low-density diskette (720 KB) containing 80x2 tracks, each with 9 sectors
3.5 inch high-capacity diskette (1.44 MB) containing 80x2 tracks, each with 18 sectors
3.5 inch high-capacity diskette (2.88 MB) containing 80x2 tracks, each with 36 sectors

The sector size is 512 bytes for all diskette types.

The format command formats a diskette with the highest capacity that is supported by the diskette drive, unless the Device parameter specifies a different density.

The format command formats a read/write optical disk, if the drive supports setting the Format Options Valid (FOV) bit of the defect list header to 0. To format a read/write optical disk, use the name of the read/write optical drive (such as /dev/romd0) after the -d flag.

Before formatting a diskette or read/write optical disk, the format command prompts for verification. This allows the user to end the operation cleanly.

Flags

Table 1. Flags
Item	Description
-d `Device`	Specifies the device that is used to format the diskette. If the device name ends with the letter `h`, the drive formats the diskette for high density. If the device name ends with the letter `l`, the drive formats the diskette for low density. Refer to the fd special file for information about valid device types. This flag is used only with the format command. Attention: If the diskette drive supports a higher capacity than the highest capacity for which the diskette was manufactured, the capacity of the diskette must be explicitly stated in the `Device` parameter (-d `Device` flag) of the format command. For example, to format a 1 MB diskette on a 4 MB diskette drive, specify the diskette capacity in the -d flag as follows: `-d /dev/fd0.9 for a 1MB diskette` Failure to do this can cause read and write errors.
-f	Formats the diskette without checking for bad tracks, thus formatting the diskette more quickly. This flag applies to diskettes only, not to read/write optical disks. It is used only with the format command.
-l	(Lowercase L) Formats a 360 KB diskette in a 5.25 inch, 1.2 MB diskette drive. Formats a 720 KB diskette in a 3.5-inch 1.4 MB diskette drive. This flag applies to diskettes only, not to read/write optical disks. It is used only with the format command. Attention: A 360 KB diskette drive cannot be able to read a 360 KB diskette that is formatted in a 1.2 MB drive.

Parameters

Table 2. Parameters
Item	Description
`Device`	Specifies the device containing the diskette to be formatted. The default is the /dev/rfd0 device for drive 0.

Examples

To format a diskette in the /dev/rfd0 device, enter:
```
format   -d   /dev/rfd0
```
To format a diskette without checking for bad tracks, enter:
```
format   -f
```
To format a 360 KB diskette in a 5.25 inch, 1.2 MB diskette drive in the /dev/rfd1 device, enter:
```
format   -l   -d   /dev/rfd1
```
To format a 3.5 inch, low-density (720 KB) diskette, enter:
```
format -d /dev/fd0.9
```
To format a 3.5 inch, high-capacity (1.44 MB) diskette, enter:
```
format -d /dev/fd0.18
```
To format a read/write optical disk in the /dev/romd0 device, enter:
```
format -d /dev/romd0
```

Files

Table 3. Files
Item	Description
/usr/sbin/format	Contains the format command.
/dev/rfd*	Specifies the device parameters.
/dev/fd*	Specifies the device parameters.
/dev/romd*	Specifies the device parameters.
/dev/omd*	Specifies the device parameters.