Disk Space Monitoring

How Server Scout Monitors Disk Usage

Server Scout automatically monitors disk usage across all mounted filesystems on your Linux servers. The monitoring agent collects data every minute, tracking both used space and available capacity for each mount point. This includes your root filesystem (/), separate partitions like /home or /var, and any additional mounted storage devices.

The system calculates usage percentages and tracks trends over time, allowing you to spot gradual increases in disk consumption before they become critical issues.

Understanding the Disk Usage Dashboard

The server detail page features a comprehensive disk usage breakdown panel that provides at-a-glance information about your storage situation.

Key Metrics Displayed

• Mount Point: Shows each filesystem path (/, /home, /var, etc.)
• Total Size: The complete capacity of each partition
• Used Space: Current consumption in both GB and percentage
• Available Space: Remaining capacity before the filesystem fills up
• Usage Trend: Visual indicators showing whether usage is increasing, stable, or decreasing

The panel uses colour coding to highlight potential issues - green for healthy usage (under 80%), amber for moderate concern (80-90%), and red for critical levels (over 90%).

Setting Up Disk Space Alerts

Proactive alerting prevents unexpected outages caused by full filesystems. Server Scout allows you to configure multiple threshold levels for each monitored mount point.

Configuring Alert Thresholds

1. Navigate to your server's settings page
2. Select the "Alerts" tab
3. Locate the "Disk Space" section
4. Set warning thresholds (recommended: 80% for warning, 90% for critical)
5. Configure notification channels (email, Slack, or webhook)
6. Save your settings

Recommended Threshold Strategy

Consider setting different thresholds based on filesystem purpose:

• Root filesystem (/): 80% warning, 90% critical
• Log partitions (/var/log): 75% warning, 85% critical
• User data (/home): 85% warning, 95% critical
• Temporary storage (/tmp): 70% warning, 85% critical

Linux Disk Space Management Best Practices

Regular Maintenance Tasks

Implement these routine practices to maintain healthy disk usage:

# Check disk usage summary
df -h

# Find large directories
du -sh /* | sort -rh | head -10

# Locate files larger than 100MB
find / -type f -size +100M -exec ls -lh {} \; 2>/dev/null

Automated Cleanup Strategies

Configure automated maintenance through cron jobs:

# Clean package cache weekly
0 2 * * 0 apt-get clean

# Remove old log files
0 3 * * * find /var/log -name "*.log.*" -mtime +30 -delete

# Clear temporary files
0 4 * * * find /tmp -type f -mtime +7 -delete

Common Causes of Unexpected Disk Usage

Understanding typical culprits helps you respond quickly to disk space alerts.

Log File Accumulation

Application and system logs often consume substantial space, particularly:

• Web server logs (/var/log/apache2/ or /var/log/nginx/)
• System logs (/var/log/syslog, /var/log/messages)
• Application-specific logs in /var/log/

Consider implementing log rotation policies and monitoring log growth patterns.

Temporary File Build-up

Several locations commonly accumulate temporary data:

• /tmp - System temporary files
• /var/tmp - Longer-term temporary storage
• User cache directories (~/.cache/)
• Package manager caches (/var/cache/apt/)

Forgotten Backups and Archives

Old backup files frequently cause space issues:

• Database dumps left in /home/ or /backup/
• Compressed archives that weren't cleaned up
• Docker images and containers consuming space
• Old kernel packages retained by the package manager

Database Growth

Monitor database storage requirements:

• MySQL data directory (/var/lib/mysql/)
• PostgreSQL data (/var/lib/postgresql/)
• Log files from database engines

Regular database maintenance, including optimisation and archiving old data, prevents unexpected growth.

Responding to Disk Space Issues

When Server Scout alerts you to high disk usage, follow this systematic approach:

1. Identify the affected filesystem using the dashboard
2. Locate space-consuming files with du and find commands
3. Safely remove unnecessary files after verification
4. Implement preventive measures to avoid recurrence
5. Adjust alert thresholds if necessary based on usage patterns

By combining Server Scout's monitoring capabilities with proactive maintenance practices, you can maintain optimal server performance and prevent disk space emergencies.