Free Space Available on DVD+RW

Question

We have software on Windows 2008 Server that formats a DVD+RW disk with UDF using Windows format.com and then copies files to the disk using CreateFile to open the file, ReadFile - WriteFile to copy the file data, FlushFileBuffers to make sure the data is really on the DVD+RW, and finally CloseHandle. Before each file is copied, we call GetDiskFreeSpaceEx to check if there is space on the DVD+RW for the file. The problem is that after many files have been copied and the disk is getting close to full our software will fail during the copy process with an error code indicating the disk is full although the previous call to GetDiskFreeSpaceEx indicated there was much more space free than was needed for the file. We cal _stati64 to get the space needed for the file. Does anybody know why this is not working? Is accessing a DVD+RW in this manner proper? I can't find any Microsoft documentation that addresses accessing DVD+RW via MFC on the new 2008 Server.

Answer 1

How close is are you getting to the disk being full before it fails?

Are you using SetEndOfFile() to avoid extending writes?