[solved] FileSetPos and FileWrite speed on hugh files

[JFX]

fsutil can create also larger than 2 GB files: e.g. fsutil file createnew c:\test.bin 3145728000

But what is the sense of fsutil file setvaliddata <size>?

Creating a file with fsutil file createnew is fast, but

If you want to access that file with filewrite it will "clear" the complete content with zeros.

But after fsutil file setvaliddata this will not happen.

Thanks to everyone, problem is solved with these two fsutil.exe calls.

[ProgAndy]

But what is the sense of fsutil file setvaliddata <size>?

Sometimes the Remarks-section in MSDN is of some use:

You can use the SetFileValidData function to create large files in very specific circumstances so that the performance of subsequent file I/O can be better than other methods. Specifically, if the extended portion of the file is large and will be written to randomly, such as in a database type of application, the time it takes to extend and write to the file will be faster than using SetEndOfFile and writing randomly.

[UEZ]

Creating a file with fsutil file createnew is fast, but

If you want to access that file with filewrite it will "clear" the complete content with zeros.

But after fsutil file setvaliddata this will not happen.

Thanks to everyone, problem is solved with these two fsutil.exe calls.

Aha, thanks for the information.

@ProgAndy: thanks also to you for your information!

Br,

UEZ

Edited March 28, 2011 by UEZ