There was no line "INFO_LOGGING=N" in dconfig.ini. I did find a whole logging section (pasted below for reference), which I was able to edit and get logging to work.
I got the fourth server to be discivered and inventory correctly after re-installing OMSA.
I will go ahead and enable CSIOR on our servers. it would be nice if this were enabled by default.
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Logging section I found in dconfig.ini:
[LOGGING]
; The master switch (true/false).
LOG_ENABLED=false
; Log to file (true/false), if true Output file is $(LOG_FILE_PREFIX)$(SEPARATOR)<appname>$(LOG_FILE_SUFFIX).
LOG_TO_FILE=false
LOG_FILE_PREFIX=c:\windows\temp
LOG_FILE_SUFFIX=_log.txt
; Filter based on tags (true/false), if true log only the statements with Tag name specified.
LOG_FILTER=false
LOG_FILTER_TAG=PPA
; Log levels are on a scale 1-7 where 7 is full verbose, trace (7), debug (6), info (5), warning (4), error (3), fatal (2), and output (1),
; and range is from Minimum scale to Maximuml scale of logging levels, you get all logging information between the range of levels specified.
LOG_LEVEL_MIN=info
LOG_LEVEL_MAX=output
; Log to Visual Studio and CMD Screen (true/false).
LOG_TO_VS=false
LOG_TO_SCREEN=false