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- From: microsoft!leefi@uunet.uu.net
- Newsgroups: comp.binaries.ibm.pc
- Subject: v03i057: dsptch, patches msdos 4.0 & 4.1 to fix bug
- Date: 13 Jun 89 03:00:15 GMT
-
- A problem was recently found in DOS versions 4.00 and 4.01 which can
- cause FAT corruption when files that are larger than 32MB in size are
- appended to. The bug is manifested if each and every of the following
- occur:
-
- 1. BUFFERS (CONFIG.SYS command) are allocated with secondary cache
- enabled.
- 2. Greater than 32MB disk partition is in effect.
- 3. The user is sequentially accessing a file and any part of that file
- falls within the range of 32MB to 32MB + 10K on the disk, and the
- portion of the file being accessed falls between that same narrow
- range.
- 4. Immediately after sequentially accessing this file, the user
- performs an operation that causes the system to read a FAT (file
- allocation table) sector.
-
- If all of these conditions are true, the result is a corruption of the
- FAT (and loss of data). The chance of all of the above occuring in the
- sequence described is remote.
-
- Microsoft has provided a patch utility that corrects this problem. The
- name of the utility is PATCH.EXE. A description file, READ.ME, is
- included to provide instruction on how to use the PATCH.EXE program.
- These two files have been archived into the archived file DSPTCH.ARC.
- This archive is available on various computer bulletin boards and
- information services, such as Microsoft OnLine and Compuserve. [And now
- probably Simtel20, if Keith Peterson sees this...]
-
- The patch, has a /F switch (ala CHKDSK), which will allow the actual
- patch to occur. Otherwise, it will not modify the DOS system file. If
- this switch is not used, PATCH.EXE will examine the boot disk and
- determine if the system needs to be patched. The system should be
- rebooted after the patch occurs.
-
- See the file READ.ME for further information.
- --
- Lee Fisher, leefi@microsof.com.UUCP, leefi@microsof.beaver.washington.EDU
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