Manage Logs
Nessus has the following log files:
- nessusd.dump — Nessus dump log file used for debugging output.
- nessusd.messages — Nessus scanner log.
- www_server.log — Nessus web server log.
- backend.log — Nessus backend log.
The following are the default log file locations for each operating system.
- Linux — /opt/nessus/var/nessus/logs/<filename>
- Mac OS X — /Library/Nessus/run/var/nessus/logs/<filename>
- Windows — C:\ProgramData\Tenable\Nessus\nessus\logs\<filename>
You can customize log file locations when you modify log settings.
To modify log settings, use one of the following methods:
You can configure log locations and rotation strategies by editing the log.json file.
Note: You cannot configure nessusd.dump settings using log.json. Configure nessusd.dump settings using advanced settings.
To modify log settings using log.json:
-
Using a text editor, open the log.json file, located in the corresponding 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
-
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 maximum rotation size or rotation time.
Valid values:
- size — rotate the log based on size, as specified in max_size.
- daily — rotate the log based on time, as specified in rotation_time.
rotation_time 86400 (1 day) Rotation time in seconds.
Only used if rotation_strategy is daily.
max_size Nessus: 536870912 (512 MB)
Agent: 10485760 (10 MB)
Rotation size in bytes.
Only used if rotation_strategy is size.
max_files Nessus:
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 are deleted.
file Depends on operating system and log file
The location of the log file. See Default Log Locations.
- Save the log.json file.
-
Restart the Nessus service.
The log settings are updated.
Linux example
{
"reporters": [
{
"tags": [
"response"
],
"reporter": {
"type": "file",
"rotation_strategy": "daily",
"rotation_time": "86400",
"max_size": "536870912",
"max_files": "1024",
"file": "/opt/nessus/var/nessus/logs/www_server.log"
},
"format": "combined"
},
{
"tags": [
"log",
"info",
"warn",
"error",
"trace"
],
"reporter": {
"type": "file",
"file": "/opt/nessus/var/nessus/logs/backend.log"
},
"context": true,
"format": "system"
}
]
}
Mac OS X example
{
"reporters": [
{
"tags": [
"response"
],
"reporter": {
"type": "file",
"rotation_strategy": "daily",
"rotation_time": "86400",
"max_size": "536870912",
"max_files": "1024",
"file": "/Library/Nessus/run/var/nessus/logs/www_server.log"
},
"format": "combined"
},
{
"tags": [
"log",
"info",
"warn",
"error",
"trace"
],
"reporter": {
"type": "file",
"file": /Library/Nessus/run/var/nessus/logs/backend.log"
},
"context": true,
"format": "system"
}
]
}
Windows example
Note: The backslash (\) is a special character in JSON. To enter a backslash in a path string, you must escape the first backslash with a second backslash so the path parses correctly.
{
"reporters": [
{
"tags": [
"response"
],
"reporter": {
"type": "file",
"rotation_strategy": "daily",
"rotation_time": "86400",
"max_size": "536870912",
"max_files": "1024",
"file": "C:\\ProgramData\\Tenable\\Nessus\\nessus\\logs\\www_server.log"
},
"format": "combined"
},
{
"tags": [
"log",
"info",
"warn",
"error",
"trace"
],
"reporter": {
"type": "file",
"file": "C:\\ProgramData\\Tenable\\Nessus\\nessus\\logs\\backend.log"
},
"context": true,
"format": "system"
}
]
}