Solved - OpenG Zlib max file size 2.00 GB?

[Grunkles]

I'm trying to automate the backup of a large number of TDMS files. I've got them sorted out by year and month, but there's usually about 20GB per month (uncompressed). I'm using the OpenG Zip library to do the compression and my first few attempts at a whole folder threw an "error 7" at 2.00 GB. It also leaves the archive in a state that is unusable by Windows.

Not a lot of useful info in the error messages from this library:

Quote

ZLIB Close Write File__ogtk.vi in ZLIB Store File__ogtk.vi->ZLIB Compress Directory__ogtk.vi->Zip TDMS files TEST.vi

Took me a few hours to sort out that if you include an archive name, you can't use the "create new" option. =/

Is this a limitation in the core zip file utility, possibly because it's 32-bit? Has anyone successfully compressed a similar size chunk of files?

Thanks in advance!

LabVIEW 2014 sp1 32-bit

OpenG Zlib 1.2.3

Win7 Pro 64-bit

Edited December 20, 2017 by Grunkles

[Grunkles]

Changed up my search query and found this thread over on the NI forums that explains the problem. Looks like it's indeed the 32-bit limitations.

[hooovahh]

Years ago I showed how you could call the 7-zip command line EXE to have it perform functions that are hard of impossible with the native LabVIEW zip, or OpenG.  I suspect that the 64 bit built EXE could perform the compression without any issue and can be called using the System Exec.  Beyond that I'm guessing you already know about TDMS defragging, and how it can save on TDMS file sizes.  After a defrag most of the data will be binary, and won't compress much anyway.  I'd suggest defragging first, and then zipping.  If your size doesn't go down in the zip it might not be worth the extra effort.