*.exrsl files from VRay

Hi,
Has anyone concluded under what circumstances VRay decides to create a *.exrsl file during rendering?
Very little information anywhere on the web and I have submitted a Chaos Group support ticket already.
Just wondering if anyone here has seen these ‘temp’ *.exrsl files created and was able to work out under what circumstances they are generated?

mailman.studiosysadmins.com/pipe … 18287.html

Thanks!
Mike

To answer my own question:

Originally V-Ray used to write tiled OpenEXR files; however reading these files in Nuke is very slow, which caused people to have to convert them manually to scanline-based OpenEXR files, or to write to .vrimg files and then use vrimg2exr to convert them to scanline-based OpenEXR files, which was an additional step. So in the latest versions, V-Ray will write the tile-based OpenEXR file, but at the end of the render will attempt to convert it automatically to a scanline-based OpenEXR file. The .exrsl file is the intermediate scanline-based OpenEXR file before the conversion is fully complete. The only way for you to see these files is if the render process is killed before V-Ray has a chance to get to the end of the render.

Best regards,
Vlado