The description below is from the book
DOS the Easy Way by Everett Murdock Ph.D.
SCANDISK
SCANDISK [d: [d: . . .]|/all][/checkonly|/autofix[/nosave]|/custom][/surface]
[/mono][/nosummary]
SCANDISK volume-name[/checkonly|/autofix[/nosave]|/custom][/mono]
[/nosummary]
SCANDISK /fragment [d:][path]filename
SCANDISK /undo [undo-d:][/mono]
Purpose: Starts the Microsoft ScanDisk program which is a disk analysis and repair tool
used to check a drive for errors and correct any problems that it finds (new
with DOS Version 6.2).
Discussion
The ScanDisk program checks and fixes the problems in
the following areas:
File allocation table (FAT)
File system structure (lost clusters, crosslinked files)
Directory tree structure
Physical surface of the drive (bad clusters)
DoubleSpace volume header (MDBPB)
DoubleSpace volume file structure (MDFAT)
DoubleSpace compression structure
DoubleSpace volume signatures
MS-DOS boot sector
ScanDisk can be used to check for errors on the
following types of drives:
Hard drives
DoubleSpace drives
Floppy disk drives
RAM drives
Memory cards
The ScanDisk program cannot be used with CD-ROM
drives, network drives, drives created by using the ASSIGN, SUBST, or JOIN commands,
and drives created by using INTERLINK.
NOTE:
You cannot run ScanDisk
when other programs are running. Also, you cannot use ScanDisk
to repair disk errors if you start it from another program, or when Microsoft
Windows or MS-DOS Task Swapper are running. However,
you can check your disk without fixing errors by using ScanDisk
with the /CHECKONLY option.
Options
/all - Used to check and repair all local drives.
/autofix - This option will fix any errors it
encounters without prompting you first. By default, when you use the /AUTOFIX
option, ScanDisk will save any lost clusters it finds
as files in the drive`s root directory. If you want ScanDisk to delete lost clusters instead of saving them,
include the /NOSAVE option. Using the /AUTOFIX option, ScanDisk
will also prompt you for an Undo disk unless you include the /NOSUMMARY option.
The /AUTOFIX command can be used in conjunction with the /CHECKONLY and /CUSTOM
options.
/checkonly - Use this option if you
want to check a drive for errors without repairing the damage. You
cannot use this switch with the /AUTOFIX or /CUSTOM options .
/custom - Use this option if you want to run ScanDisk
using the configuration settings in the Custom section of the SCANDISK.INI
file. This is useful for running ScanDisk from a ba Also prevents u cannot use this option in conjunction
with the /AUTOFIX and /CHECKONLY options.
/mono - Use this osurface scan after checking other
areas of a drive. During a surface scan of an unSPLAY=MONO
line in your SCANDISK.INI file if can be realiably
written and read from the drive being scanned. During a surface scan of a
DoubleSpace drive, ScanDisk confirms that data can be
decompressed. It is a good idea to periodically do a surface scan of all
drives.
Examples
If you want to check and fix the current drive, enter
scandisk
To check all your drives, enter
scandisk /all
This will check all your hard disk partitions, as well as all mounted
DoubleSpace drives.
h drive. Also prevents ScanDisk
from prompting you for an Undo disk if it finds errors.
/surface - Automatically performs a surface scan after checking other areas of
a drive. During a surface scan of an uncompressed drive, SCANDISK confirms that
data can be realiably written and read from the drive
being scanned. During a surface scan of a DoubleSpace drive, ScanDisk confirms that data can be decompressed. It is a
good idea to periodically do a surface scan of all drives.
Examples
If you want to check and fix the current drive, enter
scandisk
To check all your drives, enter
scandisk /all
This will check all your hard disk partitions, as well as all mounted
DoubleSpace drives.