Microsoft New Zealand’s opinion on a Windows NT file problem appears to be at odds with an assessment of the situation by its US marketing people.
Microsoft locally says an article published on its ftp site titled “Windows NT File Corruption Problem” is not about Microsoft NT Server 4.0 but about Microsoft Internet News Server, currently in beta.
However, the September 24 article from Microsoft says: “The information in this article applies to Microsoft Windows NT Workstation version 4.0 and Microsoft Windows NT Server version 4.0.”
The US article says: “If files are rapidly accessed on a Windows NT file server, intermittent data corruption may occur. Microsoft Internet News Server data files may exhibit these symptoms. The problem is more likely to be observed on a multiprocessor system.”
The article went on to state the cause.
“If an application is performing a write-extend of a file, the cache manager read ahead thread is also reading the current last page of the file as part of the larger read. The read ahead thread issues the read and the write is blocked waiting for the read to complete. Due to a timing problem that may occur, the memory manager wakes the write thread associated with the IO operation. This thread will place null characters in the last page which is beyond the current file size and then write the new data into the page. The read thread wakes up and also zeroes the last page after the write thread has written the new data. The update to the page is lost and null characters are appended in the file instead of the data which should have been committed for the IO operation.”
It then provided a fix and concludes: “Microsoft has confirmed this to be a problem in Windows NT version 4.0. A supported fix is now available, but has not been fully regression-tested and should be applied only to systems experiencing this specific problem. Unless you are severely impacted by this specific problem, Microsoft recommends that you wait for the next service pack that contains this fix.”
Microsoft New Zealand marketing manager Guy Haycock says the article and the bug pertain to Microsoft Internet News Server (code name Normandy), the beta of which was posted on Microsoft’s Web site last week.
“Microsoft Internet News Server files are the only data files involved here. We’re acknowledging users who deploy News Server on multiprocessor systems and saying they need this patch. This is quite normal in software development.”
Haycock says the fact that the problem is more likely to occur on multiprocessor systems means the likelihood of users in New Zealand being affected is extremely low.