MS DOS Command: DISKCOPY.COM

Reference from Microsoft MS-DOS cmd help

Description

Copies the entire contents of one floppy disk to another floppy disk. DISKCOPY writes over the existing contents of the destination disk as it copies the new information to it.

This command determines the number of sides to copy based on the source drive and disk.

Syntax

DISKCOPY [drive1: [drive2:]] [/1] [/V] [/M]

Parameters

drive1:	Specifies the drive containing the source disk.
drive2:	Specifies the drive containing the destination disk.

Switches

/1	Copies only the first side of a disk.
/V	Verifies that the information is copied correctly. Use of this switch slows the copying process.
/M	Forces DISKCOPY to use only conventional memory for interim storage. By default, DISKCOPY uses your hard disk as an interim storage area so you don't have to swap floppy disks.

Related Commands

For information about copying one or more files, see the COPY command.

For information about copying directories and subdirectories, see the XCOPY command.

For information about comparing two disks to see if they are identical, see the DISKCOMP command.

Remarks

Invalid drive for DISKCOPY

The DISKCOPY command works only with uncompressed removable disks, such as floppy disks. You cannot use DISKCOPY with a hard disk or a network drive. If you specify a hard disk drive for drive1 or drive2, DISKCOPY displays the following error message:

Invalid drive specification

Specified drive does not exist

or is non-removable

DISKCOPY messages

The DISKCOPY command prompts you to insert the source and destination disks and waits for you to press any key before continuing.

After copying, DISKCOPY displays the following message:

Copy another diskette (Y/N)?

If you press Y, DISKCOPY prompts you to insert source and destination disks for the next copy operation. To stop the DISKCOPY process, press N.

If you are copying to an unformatted floppy disk in drive2, DISKCOPY formats the disk with the same number of sides and sectors per track as are on the disk in drive1. DISKCOPY displays the following message while it formats the disk and copies the files:

Formatting while copying

If the capacity of the source disk is greater than that of the destination disk and your computer can detect this difference, DISKCOPY displays the following message:

Drive types or diskette types not compatible

Disk serial numbers

If the source disk has a volume serial number, DISKCOPY creates a new volume serial number for the destination disk and displays the number when the copy operation is complete.

Omitting drive parameters

If you omit the drive2 parameter, DISKCOPY uses the current drive as the destination drive. If you omit both drive parameters, DISKCOPY uses the current drive for both. If the current drive is the same as drive1, DISKCOPY prompts you to swap disks as necessary.

Using one drive for copying

When you use a single drive as both the source and destination drive, DISKCOPY stores an image of the source disk in the directory specified by the TEMP environment variable. If there is not enough space on that drive to contain the source-disk image, you might have to swap floppy disks. DISKCOPY prompts you each time you should insert a disk in the drive. DISKCOPY reads from the source disk, writes to the destination disk, and prompts you to insert the source disk again. This process continues until the entire disk has been copied.

Avoiding disk fragmentation

Because DISKCOPY makes an exact copy of the source disk on the destination disk, any fragmentation on the source disk is transferred to the destination disk. Fragmentation is the presence of small areas of unused disk space between existing files on a disk.

A fragmented source disk can slow down the finding, reading, or writing of files. To avoid transferring fragmentation from one disk to another, use either the COPY command or the XCOPY command to copy your disk. Because COPY and XCOPY copy files sequentially, the new disk is not fragmented.

Copying Startup disks

If you use the DISKCOPY command to copy a startup disk, the copy will also be a startup disk. If you use COPY or XCOPY to copy a startup disk, the copy usually will not be a startup disk.

DISKCOPY exit codes

The following list shows each exit code (ERRORLEVEL parameter) and gives a brief description of its meaning:

0	The copy operation was successful.
1	A nonfatal read/write error occurred.
2	The user pressed CTRL+C to stop the process.
3	A critical error occurred.
4	An initialization error occurred.

You can use the ERRORLEVEL parameter on the IF command line in a batch program to process exit codes returned by DISKCOPY. For an example of a batch program that processes exit codes, see the CHOICE command.