Step-by-step guide to check disk SMART attributes for health. Monitor disk wear, detect disk failures early, and prevent data loss with predictive maintenance.

Last updated: 2026-01-11

How to Check Disk SMART Attributes for Health on Linux Server

Monitor disk SMART attributes to track disk health, detect disk failures early, and prevent data loss. This guide shows you how to check SMART attributes and set up automated monitoring.

For comprehensive disk health monitoring, see Disk Health Monitoring with SMART. For troubleshooting disk issues, see Disk Space Full Server.

Why Checking SMART Attributes Matters

SMART attributes provide early warning signs of disk failure. Monitoring SMART attributes enables predictive maintenance, allowing disk replacement before catastrophic failures occur.

Method 1: Check SMART Status with smartctl

Check SMART Health Status

# Install smartmontools
sudo apt-get install smartmontools  # Debian/Ubuntu
sudo yum install smartmontools      # CentOS/RHEL

# Check SMART status
sudo smartctl -H /dev/sda

# Get SMART health summary
sudo smartctl -a /dev/sda

# Check SMART attributes
sudo smartctl -A /dev/sda

Monitor Critical SMART Attributes

# Check reallocated sectors
sudo smartctl -A /dev/sda | grep "Reallocated_Sector_Ct"

# Check pending sectors
sudo smartctl -A /dev/sda | grep "Current_Pending_Sector"

# Check uncorrectable sectors
sudo smartctl -A /dev/sda | grep "Offline_Uncorrectable"

# Check power-on hours
sudo smartctl -A /dev/sda | grep "Power_On_Hours"

Method 2: Run SMART Self-Tests

Execute SMART Tests

# Run short self-test
sudo smartctl -t short /dev/sda

# Run long self-test
sudo smartctl -t long /dev/sda

# Check self-test results
sudo smartctl -l selftest /dev/sda

# Check test progress
sudo smartctl -c /dev/sda

Method 3: Automated SMART Monitoring with Zuzia.app

Set up automated monitoring to track SMART attributes continuously and receive alerts when disk health degrades.

Step 1: Add SMART Monitoring Command

Log in to Zuzia.app Dashboard
- Access your Zuzia.app account
- Navigate to your server
- Click "Add Scheduled Task"
Configure SMART Status Check Command
```
sudo smartctl -H /dev/sda | grep -i "PASSED\|FAILED"
```
- Set execution frequency (every 30-60 minutes)
- Configure alerts when SMART status indicates problems

Step 2: Configure Alert Thresholds

Warning: Reallocated sectors > 10
Critical: Reallocated sectors > 100
Emergency: Pending sectors > 0 or SMART test failed

Step 3: Monitor Critical Attributes

Add commands to monitor critical SMART attributes:

# Check reallocated sectors count
sudo smartctl -A /dev/sda | grep "Reallocated_Sector_Ct" | awk '{print $10}'

Best Practices for SMART Monitoring

1. Monitor Critical SMART Attributes

Track reallocated sectors count
Monitor pending sector count
Check uncorrectable sector count
Watch power-on hours

2. Run Regular SMART Self-Tests

Schedule short self-tests daily
Run long self-tests weekly
Review self-test results
Act on test failures

3. Track Disk Wear Trends

Monitor SMART attributes over time
Identify disk degradation patterns
Plan disk replacements proactively
Document disk replacement schedules

4. Set Up Comprehensive Alerts

Configure alerts for critical attributes
Set up alerts for SMART test failures
Monitor disk temperature
Alert on disk health degradation

Troubleshooting Disk Health Issues

Step 1: Identify Disk Problems

When disk health issues are detected:

# Check SMART status
sudo smartctl -H /dev/sda

# Check critical attributes
sudo smartctl -A /dev/sda | grep -E "Reallocated|Pending|Uncorrectable"

# Review SMART test results
sudo smartctl -l selftest /dev/sda

Step 2: Resolve Disk Issues

Based on investigation:

Replace Failing Disks:
- Replace disks with high reallocated sectors
- Replace disks with pending sectors
- Replace disks before catastrophic failure
Optimize Disk Usage:
- Reduce disk I/O load
- Optimize disk configuration
- Implement disk redundancy

FAQ: Common Questions About SMART Monitoring

How often should I check SMART attributes?

For production servers, continuous automated monitoring is essential. Zuzia.app can check SMART attributes every 30-60 minutes, storing historical data and alerting you when disk problems are detected.

What SMART attributes indicate disk failure?

Critical SMART attributes indicating potential disk failure include high reallocated sector count, pending sectors, uncorrectable sectors, and increasing error rates. Monitor these attributes closely.

How do I know when to replace a disk?

Replace disks when SMART attributes indicate degradation, reallocated sectors increase significantly, pending sectors appear, or SMART self-tests fail. Plan replacements proactively before catastrophic failure.

Can SMART monitoring impact disk performance?

SMART monitoring has minimal impact on disk performance when done correctly. Use efficient monitoring tools, schedule checks during low-traffic periods, and avoid excessive SMART self-tests during peak usage.

Related guides
- Disk Health Monitoring with SMART - Predictive Maintenance Best Practices
- Disk Monitoring Deep Dive - Understanding Storage Metrics
Related recipes
- How to Check Disk SMART Health Status on Linux Server
Related problems
- Disk Full Emergency - Free Up Space in 5 Minutes
- High Disk I/O Performance Impact

How to Check Disk SMART Attributes for Health on Linux Server