CHKDSK and File Allocation Adjustments (38113)


The information in this article applies to:

  • Microsoft MS-DOS operating system 3.1
  • Microsoft MS-DOS operating system 3.2
  • Microsoft MS-DOS operating system 3.21
  • Microsoft MS-DOS operating system 3.3
  • Microsoft MS-DOS operating system 3.3a
  • Microsoft MS-DOS operating system 4.0
  • Microsoft MS-DOS operating system 4.01
  • Microsoft MS-DOS operating system 5.0
  • Microsoft MS-DOS operating system 5.0a
  • Microsoft MS-DOS operating system 6.0
  • Microsoft MS-DOS operating system 6.2
  • Microsoft MS-DOS operating system 6.21
  • Microsoft MS-DOS operating system 6.22
This article was previously published under Q38113

SUMMARY

CHKDSK uses the File Allocation Table (FAT) to determine the condition of both of the following:

  • Disks as a whole
  • Files

MORE INFORMATION

The size of every file is stored in the file's directory entry. The chain size of any file is defined to be the number of clusters on the disk that it occupies multiplied by the number of bytes in each cluster. CHKDSK compares the two reported sizes to see if the directory entry and the FAT are comparable. CHKDSK displays the error message "Allocation error, size adjusted" if the sizes are incorrect.

The error is displayed when either of the following conditions is met:

  • The file size located in the directory entry is larger than the chain size. -or-

  • The chain size is more than one cluster size larger than the reported file size.
To adjust the size of the file, CHKDSK changes the directory entry to match the chain size.
Modification Type:MajorLast Reviewed:5/12/2003
Keywords:KB38113
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