Preallocating Space for File Write in LabVIEW

[test001only]

When copying files of huge size in Windows, I have seen that Windows allocates block of memory required for that file even before it starts copying it. How to do the same using LabVIEW? I actually want to allocate contiguous memory if available. I have tried using Set file size VI, but it does not seem to allocate memory for the file.

[LAVA 1.0 Content]

The function 'Set File Size' can do that.

My testing shows that the filesize has changed to the value I choose.

Ton

[Rolf Kalbermatter]

QUOTE (test001only @ Dec 12 2008, 04:02 AM)

When copying files of huge size in Windows, I have seen that Windows allocates block of memory required for that file even before it starts copying it. How to do the same using LabVIEW? I actually want to allocate contiguous memory if available. I have tried using Set file size VI, but it does not seem to allocate memory for the file.

Do you mean memory or disk space? For the first it obviously won't work as the file on disk is not loaded into memory unless you do an explicit file read. The later I'm 100% sure does work as I use that for instance in some data logger applications to make sure that the file is properly allocated without having to worry about disk full issues during the logging itself.

Rolf Kalbermatter

[Gary Rubin]

QUOTE (test001only @ Dec 12 2008, 03:02 AM)

When copying files of huge size in Windows, I have seen that Windows allocates block of memory required for that file even before it starts copying it. How to do the same using LabVIEW? I actually want to allocate contiguous memory if available. I have tried using Set file size VI, but it does not seem to allocate memory for the file.

Ben (aka neB) has http://forums.lavag.org/So-many-binary-file-options-t5506.html&p=21758#entry21758' target="_blank">written about this in the past.