I was downloading posts of combined sizes below 10 GB, mostly 1.5-5 GB. My threshold was set to 20 GB. When I ran out of space I freed up 190 GB - not only the already downloaded rars were not extracted, but also posts added to the download list after that were downloaded but status kept showing 0 pars and nothing was extracted - until I restarted NewsBin. It is now too late to look in the log, but I will the next time I ran out of free space. Perhaps this disabling of AutoPAR will not happen again.
Come to think of it, it was not the very first time I ran out of free space with RC8. Just a few hours earlier I was downloading with unrar path assigned to a non-default drive and ran out of space on the default drive anyway.
In that case there was no problems.
Everything resumed as normal after freeing up some space on the default drive. This time all the downloading and unrarring was done to the default drive when the auto-disabling of AutoPAR occurred.
NOTE:
The "default drive" is the drive to which all the download paths in the .nbi file point. In my case, the NBData folder is on yet another drive but actual chunks are on the "default drive", a junction point is used to achieve that. I think this circumstance has nothing to do whatsoever with the problem.
Except one interesting point: the remaining free space should be checked on the drive to which the actual downloading or unrarring is done. So, in some cases - on multiple different drives, one at a time. I wonder if it is done or not.
For example, if both the download path and the unrar path are reassigned to a different drive, the check of free space on the default drive should not be done even when it goes below the threshold value - because nothing is being downloaded to that drive. But because I am using a junction point to place chunks on the default drive, it would be bad for me. I am still using the default drive but NewsBin does not know about it. If you always stop NewsBin when the free space on the "default drive" drops below the threshold value - it is probably wrong but it is good for me