TDMS Defragment Function crashes labview

[yura_beno]

Trying to figure how to search for CARs, a link could be useful.

[Hooovahh]

When the CAR is created there isn't anything to link to.  Once the CAR has been addressed in some release of software it is often listed in the Upgrade Notes.  I usually do something like a search on google with site:ni.com to limit to NI's site.  I just did the search and nothing useful came up so I expect this hasn't been fixed in 2017 SP1.  It is possible it will be listed as a fix in future versions of LabVIEW.

[AshwiniWini]

Hi,

I am facing same issue with LabVIEW 2021 32 bit, when I am defragmenting tdms file of 2GB size. It works fine with ~600MB file but, crash LabVIEW and reboot Real time target (cRIO 9048).

I also observed that while LabVIEW is trying to defragment this big file, it deletes index file but index file never recovered and original .tdms file remains same as it was before.

Can you please help me to fix this issue, as it became critical in the field.

[Hooovahh]

If this is an issue with LabVIEW defrag function you should try to report it to NI to see if they can fix it.  The suggestion I have for a temporary fix, is to split that TDMS file at some valid chunk, roughly half way through the file, then defrag that portion, then append the second section and try to defrag again.  TDMS files are written in chunks and these can be found by looking for the TDSm section.  Here is a more detailed document on the file format. If the first half defrags, but the second doesn't, maybe there is something wrong with the TDMS file itself.  The defrag function still shouldn't stop like that, and should return an error.

Another suggestion I have is to defrag the file, but get the progress and see at which point it dies.  Open the Example Finder and Search for the TDMS Display Defragmentation Progress.vi.  This shows how to defrag a file, and check on the progress.  I'm curious if the crash happens at the end, which again makes me think the end of the file has some corruption.