DOCUMENT:Q150302 09-AUG-2001 [winnt] TITLE :Overlapped I/O to Tape Results In Data Corruption PRODUCT :Microsoft Windows NT PROD/VER:winnt:3.51 OPER/SYS: KEYWORDS: ====================================================================== ------------------------------------------------------------------------------- The information in this article applies to: - Microsoft Windows NT Workstation version 3.51 - Microsoft Windows NT Server version 3.51 ------------------------------------------------------------------------------- SYMPTOMS ======== Data corruption occurs when you write data to the Windows NT 3.51 tape drivers using overlapped I/O. The Windows NT backup program NTBackup.exe does not support overlapped I/O, so this problem only affects developers writing third-party backup software for Windows NT. CAUSE ===== The data corruption occurs because the tape drivers do not zero out the QueueSortKey in the SCSI Request Block (SRB) before submitting the SRB to the SCSIPort driver. As a result, random values are placed in the QueueSortKey, causing overlapped writes to be committed to tape out of order. RESOLUTION ========== Change the tape drivers to set the QueueSortKey to zero before submitting write requests to the SCSIPort driver. STATUS ====== Microsoft has confirmed this to be a problem in . This problem was corrected in the latest Windows NT 3.51 U.S. Service Pack. For information on obtaining the Service Pack, query on the following word in the Microsoft Knowledge Base (without the spaces): S E R V P A C K Additional query words: 3.51 prodnt ====================================================================== Keywords : Technology : kbWinNTsearch kbWinNTWsearch kbWinNT351search kbWinNTW351search kbWinNTW351 kbWinNTSsearch kbWinNTS351 kbWinNTS351search Version : winnt:3.51 ============================================================================= THE INFORMATION PROVIDED IN THE MICROSOFT KNOWLEDGE BASE IS PROVIDED "AS IS" WITHOUT WARRANTY OF ANY KIND. MICROSOFT DISCLAIMS ALL WARRANTIES, EITHER EXPRESS OR IMPLIED, INCLUDING THE WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE. IN NO EVENT SHALL MICROSOFT CORPORATION OR ITS SUPPLIERS BE LIABLE FOR ANY DAMAGES WHATSOEVER INCLUDING DIRECT, INDIRECT, INCIDENTAL, CONSEQUENTIAL, LOSS OF BUSINESS PROFITS OR SPECIAL DAMAGES, EVEN IF MICROSOFT CORPORATION OR ITS SUPPLIERS HAVE BEEN ADVISED OF THE POSSIBILITY OF SUCH DAMAGES. SOME STATES DO NOT ALLOW THE EXCLUSION OR LIMITATION OF LIABILITY FOR CONSEQUENTIAL OR INCIDENTAL DAMAGES SO THE FOREGOING LIMITATION MAY NOT APPLY. Copyright Microsoft Corporation 2001.