datalog file size limit

[crimolvic]

Hi all,

I am performing continuous buffered data acquisition and saving it to disk. For this late popuse I am making use of the datalog file VI family (Open/create/replace datalog - write datalog and close file). However when the file reach the 4,2 Gbytes I get an error with code 1. Moreover, I am unable to open the file so I loose my acquired data.

The problem is that I need to acquire more than 4,2Gbytes of data. Does anybody know how can I workaround this error? is 4,2Gbytes the limit for this type of files? If yes, can I enlarge this limit?

thanking in advance,
CJMV

[RavensFan]

What OS do you have?  How is your harddrive formatted (FAT32, NTFS)?  A 4 GB file sounds like it would be a limit on a Windows machine.  I googled it and came across sources that said ~4GB is the file size limit for a FAT32 system.

Check out this link.

I think your work around would be closing files as they approach 4GB and opening a new file.

[DFGray]

Before LabVIEW 8.2, LabVIEW file pointers were 32 bit.  That limits the size of the file to 4GBytes.  If you want to create files larger than 4GBytes on LabVIEW 8.0 or earlier, use NI-HWS.  At LabVIEW 8.2 and above, file pointers were changed to 64-bit and a new file format - TDMS - was introduced.  Both also allow file sizes over 4GBytes.  NI-HWS remains available and supported.

The remaining piece is that your file system must support file sizes over 4GBytes.  If you are using a Windows operating system, you must use NTFS.  FAT16 and FAT32, as mentioned above, are limited to 4GBytes or less.  Windows has a utility to convert FATxx systems to NTFS.  Note that NTFS is less efficient than FAT32, so if you are limited by your stream-to-disk speed, be careful.  This is only an issue in very high-speed applications.  If you are using a native Linux or MacOSX file system, you should have no difficulties.

[crimolvic]

I am using LV 8.2, Windows XP and NTFS format. My work around for the moment was the same that the one Ravens Fan propose.

but from what DFGray said, with my configuration I could also use the TDMS files format.

thank you both for your answers!!!

CJMV