Knowledge Base

Overlapped I/O to Tape Results In Data Corruption

Article ID: 150302

Article Last Modified on 11/1/2006

Microsoft Windows NT Workstation 3.51
Microsoft Windows NT Server 3.51

This article was previously published under Q150302

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 <product and version>. 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: KB150302