28 GB log file in case directory from ingestion of a 300 GB HDD

Specifically the autopsy.log.0 file. There are no other log files in this directory other than a 0 KB autopsy.log.0.lck file.

The ingestion has been running for approximately 20 hours, and it continues to process .mst files at a gradually slowing rate of speed. I note that I noticed that this log file was unusually large (1.8 GB) within an hour or so of beginning the ingestion of this drive. I attempted to open the file at that time, but nothing could open the file.

Is this normal? If not, I assume writing to this multi-GB log file could be causing problems with the ingestion process, correct?

If you look at the bottom right-hand corner of Autopsy GUI are there any errors showing? If you were able to look at the log file you will probably see lots of errors. To look at the file you will need a editor that can handle big files or do more on the file to see if you can find the errors that are happening.