Logging levels

The ability to vary the verbosity of log output is useful when switching between a troubleshooting session and a normal operational session. The default logging level of 1 provides some useful informational logging level of 1 provides some useful informational logs along with the fatal errors indicative of a problem.

As of this writing, there are 108 different logging defines in the source, covered through 11 distinct verbosity levels. The majority of troubleshooting at an administrative level I've seen has not needed to go past verbosity 4 though there are exceptions, like when a firewall issue is suspected.

The following table provides a brief description of each level and provides the primary key log messages provided at that level. After the table, log samples showing a few different key levels are provided to illustrate the level of detail:

[n]	Included messages at verbosity level
0	Only fatal errors are logged.
1	Informational messages are also logged. Most...