Microsoft KB Archive/32169

= FASTOPEN Harmful If Used with Disk Optimizers/Cachers =

Article ID: 32169

Article Last Modified on 5/12/2003

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APPLIES TO


 * Microsoft MS-DOS 3.1
 * Microsoft MS-DOS 3.2 Standard Edition
 * Microsoft MS-DOS 3.21 Standard Edition
 * Microsoft MS-DOS 3.3 Standard Edition
 * Microsoft MS-DOS 3.3a
 * Microsoft MS-DOS 4.0 Standard Edition
 * Microsoft MS-DOS 4.01 Standard Edition
 * Microsoft MS-DOS 5.0 Standard Edition
 * Microsoft MS-DOS 5.0a
 * Microsoft MS-DOS 6.0 Standard Edition
 * Microsoft MS-DOS 6.2 Standard Edition
 * Microsoft MS-DOS 6.21 Standard Edition
 * Microsoft MS-DOS 6.22 Standard Edition

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This article was previously published under Q32169



SUMMARY
Using the FASTOPEN command with commercial disk optimizers or disk-caching software can cause damage to the hard disk's file system.

Do not use software that performs INT 26h or INT 13h absolute disk writes, such as disk-caching or disk-optimizing software, with FASTOPEN loaded. Before using such software, remove the FASTOPEN statement from the file CONFIG.SYS and reboot the computer.



MORE INFORMATION
Because MS-DOS does not need to read the FAT table each time these files are accessed, FASTOPEN stores the locations of files and directories in memory, making access to these files faster than normal. When a disk optimizer moves files around with absolute disk writes (INT 26h), the location of the file on the file system has changed. However, FASTOPEN does not realize that the file has been moved, and keeps its outdated map of the file in memory. If the file is accessed after the disk optimization, the file is not properly read. This can cause file-system integrity problems.

Additional query words: 6.22 5.00 5.00a 6.00 6.20 windows win30 smart drive smartdrive smartdrv

Keywords: KB32169

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