The Avanti log file is enabled by default.  This file logs the emulator startup, shutdown, runtime, and error messages.  6 log files are retained by default. A version number appended to each log file name denotes past log files.  A fresh log file is created each time the emulator is launched.

Current Log:                .log
Previous Log:                .log;-1
  ...
Oldest Retained Log:        .log;-5

filename
Each logfile component requires a file name. The configuration utility initially uses <base>.log for the main emulator log, where <base> represents the configuration file name without its extension when saved. Select a writable file location using the Log file controls; the emulator must have permission to create the file and rotate its predecessors. A file-open failure prevents that logfile component from starting.

versions (default: 6; range: 1 through 500)
The count includes the current file. With 6, normal startup rotation keeps the current file plus up to five predecessors, ;-1 through ;-5. With 1, the previous current file is replaced without retaining it. Rotation takes place when the logfile component is created, not at a size limit or daily interval. Reducing the count does not automatically purge every older suffix left by a previously larger count.

Use a distinct file name for each main or serial-port logger and each running emulator. Logging components do not coordinate rotation of a shared file. The count is not a backup guarantee: preserve needed logs separately, and check file-system permissions or file locks if rotation fails. A long-running session can produce a large file even with a small versions count.

Line timestamps and optional host-header information are described under Logfile [+]. Review logs before sharing them: headers include licensing information and may include host details; serial output can contain guest data.