The "ff_debug" Command

The ff_debug command in ChromeOS manages debug tags and logging levels for flimflam, the network management system. This section explains how to use this debugging tool effectively.

Command Overview

The basic syntax for the command is:

ff_debug [<tag_expression>] [--level <level>] [--persist]
ff_debug --help
ff_debug --reset
ff_debug --list_valid_tags

Understanding Debug Tags

Tag Expressions

The command uses boolean notation: - + adds a debug tag - - removes a debug tag - Tags without operators replace existing tags

Debug Levels

Level 4 (LOG_FATAL): Most critical only
Level 0 (LOG_INFO): Standard information
Levels below 0: Verbose logging (SLOG)

Using the Command

Basic Operations

View current settings:
```
ff_debug
```
List valid tags:
```
ff_debug --list_valid_tags
```
Reset all settings:
```
ff_debug --reset
```

Tag Management

Set specific tags:
```
ff_debug network+wifi
```
Modify existing tags:
```
ff_debug +network-service
```

Log Level Control

Set log level:
```
ff_debug --level 0
```
Enable verbose logging:
```
ff_debug --level -4
```

Persistent Settings

Save configuration:
```
ff_debug [options] --persist
```

Best Practices

Debug Configuration

Initial Setup
Check current settings
List available tags
Plan debug strategy
Consider persistence
Tag Selection
Choose relevant tags
Consider combinations
Plan modifications
Document changes

Log Management

Level Selection
Match debugging needs
Consider volume
Monitor impact
Adjust as needed
Resource Usage
Watch storage usage
Monitor performance
Check system impact
Manage log size

Common Use Cases

Safety Considerations

System Impact

Performance
Log volume
Storage usage
Processing overhead
Memory impact
Resource Management
Monitor usage
Clean up logs
Reset when done
Manage persistence

Troubleshooting

Common Issues

Configuration Problems
Invalid tags
Level conflicts
Persistence issues
Reset failures
Resolution Steps
Check valid tags
Verify syntax
Reset settings
Rebuild configuration