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Manage Logs Using log.json

You can configure the size and location of log data by editing the log.json file.

  1. Using a text editor, open the log.json file, located in the following directory:

    • Linux: /opt/nessus/var/nessus/log.json
    • Mac OS X: /Library/Nessus/run/var/nessus/log.json
    • Windows: C:\ProgramData\Tenable\Nessus\nessus\log.json
  2. For each reporters[x].reporter, add or modify the following parameters.

    Parameter Default value Description
    rotation_strategy size

    Determines whether the log archives files based on rotation time or maximum rotation size.

    If you set the rotation strategy to daily, the log rotates based on rotation_time. If you set the rotation strategy to size, the log rotates based on max_size.

    rotation_time 86400 (1 day)

    Rotation time in seconds.

    Used if rotation_strategy is daily.


    Scanner: 536870912 (512 MB)

    Agent: 10485760 (10 MB)

    Rotation size in bytes.

    Used if rotation_strategy is size.


    Scanner: 100

    Agent: 2

    Maximum number of files allowed in the file rotation.

    The maximum number includes the main file, so 10 max_files is 1 main file and 9 backups. If you decrease this number, old logs will be deleted.


    Depends on operating system and log file

    The location of the log file.

    The following are the default paths for each operating system:

    Linux: /opt/nessus/var/nessus/logs/<filename>

    Mac: /Library/Nessus/run/var/nessus/logs/<filename>

    Windows: C:\ProgramData\Tenable\Nessus\nessus\logs\<filename>

  3. Save the log.json file.
  4. Restart the Nessus service.

    The log settings are updated.

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