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BSOD 1.2 RC2

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Posted: 11/16/2007 07:11:44
by Petr Chmelar (Basic support level)
Joined: 07/30/2007
Posts: 24


we have a system that is storing data in flat files and references to them in database. To present the data as a file system we use CBFS.
Now, our implementation uses memory mapped files to access the data in the flat files with the mapped file being created with GENERIC_READ | GENERIC_WRITE access, SHARE_READ and SHARE_WRITE and flags RandomAccess, WriteThrough. The mapping is created with PageReadWrite and for the whole flat file.

At beginning the CBFS was set up not to use cache (i.e. UseSystemCache = false) and SerializeCallbacks set to true. With this configuration we were getting some system deadlocks which we solved (?) by setting the UseSystemCache to true. It removed the deadlocks we were experiencing during writes but now we are getting deadlocks while reading the data back and the last time the whole server went down with BSOD. Also I encountered some read problems on Vista which were not happening on Server 2003 (SP2). It seemed to read the data from our backend system ok, then it started copying the data from our internal buffer via CBFS to the client app (explorer) but in about 50-70% it stopped with message "Error write data to ..., please remove the write protection". It seems that the problem was somewhere in CBFS because according to our logs the data was read correctly from backend.

Is there any limitations to using memory mapped files to access data while using CBFS or do you have any ideas why this could be happening?

Thank you,
Petr Chmelar

PS: The dump files are enclosed

[ Download ]
Posted: 11/16/2007 08:42:59
by Eugene Mayevski (EldoS Corp.)

Thank you very much for report. Please post the BSOD reports to HelpDesk - they are usually of no use for other users. Of course, if there's a question or a usage scenario in your message, they can be interesting for others, but the reports themselves are unlikely to be interesting :).

Sincerely yours
Eugene Mayevski



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