CHKDSK + Checking Disk Space
Reports disk size, space available, and RAM available. Also
reports and optionally corrects internal disk errors.
PC-DOS 2.0+ (revised from 1.0)
MS-DOS equivalent: CHKDSK (2.0+, revised from 1.0)
[d:][path] CHKDSK [cd:][cpath][cfilename][V]
[d:][path] Specifies the drive letter and
path name containing the
CHKDSK command file.
[cd:][cpath][cfilename] Specifies the file or files
(if wildcards are used) to be
checked. If omitted, all files
in the current directory are
/F Fixes errors in the File
Allocation Table (FAT).
/V Provides file names as it
examines them so that you can
see where errors occur.
CHKDSK is often used to verify the internal organization of
a disk or to check the amount of space available. It can also be
used to test for fragmented files. With the /F option, CHKDSK can
be used to repair common internal disk errors.
checks drive C, reporting any internal errors as well as disk
size, free space, and available RAM.
checks the disk in drive B while fixing any internal errors it
finds. You will be asked whether you wish to recover any lost
data sectors (allocation units) into data files. If you respond
Y, each lost allocation unit is recovered into its own file,
named FILEnnn.CHK. You can inspect the recovered units by using
the TYPE or DEBUG command. If they are needed, you can RENAME
them again or concatenate them using COPY; if not, you can delete
checks the file named REPORTS, reporting any noncontiguous areas
on the disk that are occupied by the REPORTS file. The more
noncontiguous areas CHKDSK reports, the greater the fragmentation
on the disk, which reduces disk operation speed. To eliminate
fragmentation, issue the BACKUP, FORMAT, and RESTORE commands to
back up the disk, reformat it, and then restore the backed-up
files to the disk, respectively.
checks the disk in drive B, repairing it while displaying a
series of messages indicating its progress and status.
All specified file(s) are contiguous
The files you specified are not fragmented (that is, they are not
stored in noncontiguous areas).
Cannot CHKDSK a network drive
You cannot use CHKDSK to check a network drive or a disk that is
being shared on a network. If the disk is shared, have the server
pause and then perform CHKDSK.
Cannot CHKDSK a SUBSTed or ASSIGNed drive
The SUBST command hides information that CHKDSK needs. Remove the
substitution and try again.
CHDIR..failed, trying alternate method
CHKDSK could not change directories. Restart DOS and issue CHKDSK
Convert lost chains to files (Y/N)?
Respond Y to convert lost data blocks to files. If you have used
the /F option, each chain will be recovered into a separate file.
If you enter N, CHKDSK frees the blocks so that they can be
allocated to new files.
Directory is joined,
tree past this point not processed.
The JOIN command has been used to join the drive to another
device. CHKDSK skips over joined devices.
Directory to file (Y/N)?
The directory that is being checked contains too much invalid
information to continue to be used as a directory. Enter Y to
convert the directory to a file that can be examined with DEBUG.
Enter N if you do not want the directory to be changed to a file.
Disk error reading/writing FAT x
The x portion of the FAT could not be updated. If this message
appears twice for FATs 1 and 2, format the disk. If FORMAT fails,
the disk is probably unusable.
[.].Entry has a bad attribute
(or size or link)
One period preceding this message indicates that the current
directory is in error; two periods indicates the parent
directory. Use the /F option to correct the error.
Error found, F parameter not specified
Corrections will not be written to disk
CHKDSK is analyzing but not correcting the disk. To correct the
disk, use the /F option.
File is cross-linked
on cluster xx
The same data block is linked to two different files.
filename Allocation error for file, size adjusted
The file allocation table contains an invalid file allocation
unit. The file is truncated after the last valid file allocation
filename Contains invalid cluster
The file has an invalid pointer. If you have used the /F option,
the bracketed message is also reported.
filename Contains xxx non-contiguous blocks
The reported number of noncontiguous areas were found for that
filename File cluster number is invalid
[, entry truncated]
The file contains an invalid pointer. If you have used the /F
option, the file will be truncated and the bracketed message will
Insufficient room in root directory
Erase files from root and repeat CHKDSK
There is not enough room to convert lost blocks to files.
Invalid current directory
An unrecoverable read error was located on the disk; no action is
path Convert directory to file (Y/N)?
The directory has been determined to no longer be usable. Respond
Y to convert it to a file.
path Invalid subdirectory
The subdirectory contains invalid information. CHKDSK attempts to
correct the error. Use the /V option for more information.
Probable non-DOS disk.
Either the disk being checked is not formatted properly or it is
badly damaged. If you have not specified the /F option,
responding Y tells CHKDSK to indicate corrective actions but not
to perform them.
Processing cannot continue,
This message is followed by another message that indicates the
reason CHKDSK is unable to continue.
Tree past this point not
Track 0 on the disk is bad, so the path past the directory that
is currently being checked could not continue.
Unrecoverable error on directory
An error was encountered in the directory; no action is required.
xxxxxxxxx bytes disk space freed
The indicated number of bytes of disk space was not allocated and
therefore was freed.
xxx lost clusters found in yyy chains
The indicated number of lost data blocks were not associated with
Running CHKDSK with the /F option can result in losing some
information, so you should first run CHKDSK without the /F
option. If CHKDSK reports errors, use the COPY command to copy
the files off the disk as backup; then run CHKDSK /F. If you
specify a file name or use the wildcard pattern *.*, CHKDSK
reports the number of noncontiguous areas that the file(s) occupy
on the disk. Version 1.0 of the command did not report available
disk space, hidden files, user files, and bad sectors. It
automatically ran with the /F option, fixing the disk while
[For related topics, press R]
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