How to Monitor RAID Array Status and Health on Linux
Monitor RAID array status and health on Linux servers. Track RAID degradation, detect disk failures, monitor rebuild progress. Setup monitoring with Zuzia.app.
How to Monitor RAID Array Status and Health on Linux
Need to monitor RAID array status and health on your Linux server? Want to track RAID degradation, detect disk failures, and monitor rebuild progress? This guide shows you how to monitor RAID arrays using built-in Linux commands and set up automated monitoring with Zuzia.app.
For comprehensive RAID monitoring strategies, see RAID Arrays Health Monitoring Guide. For troubleshooting RAID issues, see RAID Array Degradation Failures.
Why Monitoring RAID Array Status Matters
RAID array monitoring helps you detect disk failures early, track array degradation, monitor rebuild progress, prevent data loss, maintain storage redundancy, and ensure reliable storage operations. Regular RAID monitoring prevents multiple disk failures from causing data loss.
Method 1: Monitor Software RAID (mdadm) Status
For Linux software RAID, use mdadm commands:
Check RAID Array Status
# View all RAID arrays
cat /proc/mdstat
# Check RAID array details
mdadm --detail /dev/md0
# Show RAID array status
mdadm --examine /dev/sda1
# Monitor RAID arrays continuously
watch -n 1 'cat /proc/mdstat'
The /proc/mdstat file and mdadm command provide comprehensive RAID array status.
Check Individual Disk Status
# Check disk status in array
mdadm --detail /dev/md0 | grep -A 10 "Number"
# Examine disk for errors
mdadm --examine /dev/sda1
# Check disk state
cat /proc/mdstat | grep -E "\[.*\]"
# List failed disks
mdadm --detail /dev/md0 | grep -i "failed\|removed"
Individual disk status shows which disks are active, failed, or spare.
Monitor RAID Rebuild Progress
# Check rebuild progress
cat /proc/mdstat | grep -A 5 "recovery\|resync"
# Monitor rebuild continuously
watch -n 1 'cat /proc/mdstat | grep -A 5 "recovery\|resync"'
# Check rebuild speed
cat /sys/block/md0/md/sync_speed_min
# Calculate rebuild percentage (if available)
cat /proc/mdstat | grep -oP "recovery.*\d+%"
RAID rebuild progress monitoring is critical for restoring redundancy after disk replacement.
Method 2: Monitor Hardware RAID Status
For hardware RAID controllers, use vendor-specific tools:
Check LSI MegaRAID Arrays
# Check array status (if MegaCLI available)
/opt/MegaRAID/MegaCLI -LDInfo -Lall -aALL
# Check physical disk status
/opt/MegaRAID/MegaCLI -PDList -aALL
# Check virtual disk status
/opt/MegaRAID/MegaCLI -LDInfo -Lall -aALL | grep -i "state\|progress"
LSI MegaRAID provides detailed array and disk status information.
Check Adaptec RAID Arrays
# Check controller status (if arcconf available)
arcconf getconfig 1
# Check logical drive status
arcconf getconfig 1 LD
# Check physical drive status
arcconf getconfig 1 PD
Adaptec RAID controllers provide comprehensive monitoring through arcconf.
Check HP Smart Array
# Check controller status (if hpssacli available)
hpssacli ctrl all show status
# Check logical drive status
hpssacli ctrl slot=0 ld all show
# Check physical drive status
hpssacli ctrl slot=0 pd all show
HP Smart Array provides detailed RAID monitoring capabilities.
Method 3: Monitor Disk Health with SMART
SMART provides disk health information for RAID disks:
Check SMART Status
# Install smartmontools (if not installed)
# sudo apt-get install smartmontools # Debian/Ubuntu
# sudo yum install smartmontools # CentOS/RHEL
# Check SMART status
smartctl -a /dev/sda
# Check SMART health status
smartctl -H /dev/sda
# Check SMART attributes
smartctl -A /dev/sda
SMART provides disk health information and failure prediction.
Monitor SMART Attributes
# Check specific SMART attributes
smartctl -A /dev/sda | grep -E "Reallocated|Pending|Uncorrectable"
# Check disk temperature
smartctl -A /dev/sda | grep -i temperature
# Check disk error log
smartctl -l error /dev/sda
# Monitor all RAID disks
for disk in /dev/sda /dev/sdb /dev/sdc; do
echo "Checking $disk:"
smartctl -H $disk
done
SMART attributes indicate disk health and potential failure risks.
Method 4: Automated RAID Array Monitoring with Zuzia.app
Manually checking RAID arrays works for troubleshooting, but for production Linux servers, you need automated RAID monitoring that alerts you when disk failures or array degradation are detected.
Setting Up Automated RAID Monitoring
-
Add Scheduled Task in Zuzia.app Dashboard
- Navigate to your server in Zuzia.app
- Click "Add Scheduled Task"
- Choose "Command Execution" as the task type
-
Configure RAID Status Check Command
- For software RAID:
cat /proc/mdstat - For software RAID details:
mdadm --detail /dev/md0 - For hardware RAID: Use vendor-specific commands
- Set execution frequency: Every 5-15 minutes
- Configure alert conditions: Alert when array degraded or disk failed
- For software RAID:
-
Set Up Notifications
- Choose notification channels (email, webhook, Slack, etc.)
- Configure alert thresholds (e.g., alert if array degraded, disk failed)
- Set up escalation rules for critical RAID issues
- Configure different alert levels for different RAID levels
Monitor Specific RAID Arrays
For critical RAID arrays, create dedicated monitoring tasks:
# Check software RAID status
cat /proc/mdstat
# Check RAID array details
mdadm --detail /dev/md0
# Check disk SMART status
smartctl -H /dev/sda
# Check for RAID errors
dmesg | grep -i "md\|raid\|disk.*error"
Zuzia.app stores all command outputs in its database, allowing you to track RAID array health over time, identify disk failures early, and detect array degradation before it causes data loss.
Best Practices for Monitoring RAID Arrays
1. Monitor RAID Arrays Continuously
Monitor RAID arrays every 5-15 minutes. Disk failures can occur at any time, so continuous monitoring helps detect failures immediately. Use Zuzia.app automated monitoring to monitor RAID arrays continuously without manual intervention.
2. Monitor Both Array and Disk Health
Monitor at multiple levels: array status, individual disk status, and disk health (SMART). Array-level monitoring shows overall RAID health, while disk-level monitoring helps predict failures before they occur.
3. Track Rebuild Progress Closely
During RAID rebuilds, monitor rebuild progress continuously. Rebuilds can take hours or days, and array is vulnerable during rebuild. Set up alerts to monitor rebuild completion and detect rebuild failures.
4. Monitor Disk Health Proactively
Use SMART monitoring to predict disk failures before they occur. Replace disks proactively when SMART attributes indicate impending failure. This prevents array degradation and reduces rebuild time.
5. Plan Disk Replacements
Use RAID monitoring data for planning disk replacements. Keep spare disks available for quick replacement. Plan disk replacements during maintenance windows. Make data-driven decisions about disk replacements.
Troubleshooting Common RAID Monitoring Issues
Array Shows Degraded Status
If RAID array shows degraded status:
# Check array status
cat /proc/mdstat
mdadm --detail /dev/md0
# Identify failed disk
mdadm --detail /dev/md0 | grep -i "failed\|removed"
# Check disk health
smartctl -a /dev/sda
# Plan disk replacement
Degraded arrays need immediate attention to restore redundancy.
Disk Failure Detected
If disk failure is detected:
# Verify disk failure
mdadm --detail /dev/md0 | grep -i "failed"
# Check disk status
smartctl -a /dev/sda
# Remove failed disk (if safe)
# mdadm --manage /dev/md0 --remove /dev/sda1
# Add replacement disk
# mdadm --manage /dev/md0 --add /dev/sdb1
Replace failed disks immediately to restore redundancy.
Rebuild Progress Stalled
If rebuild progress stalls:
# Check rebuild status
cat /proc/mdstat | grep -A 5 "recovery\|resync"
# Check rebuild speed
cat /sys/block/md0/md/sync_speed_min
# Check for errors
dmesg | grep -i "md\|raid\|error"
# Restart rebuild if needed (advanced)
Investigate rebuild stalls and resolve underlying issues.
FAQ: Common Questions About Monitoring RAID Arrays
How often should I monitor RAID arrays on my Linux server?
We recommend monitoring RAID arrays every 5-15 minutes. Disk failures can occur at any time, so frequent monitoring helps detect failures immediately. For critical systems, monitor more frequently. Use Zuzia.app automated monitoring to monitor RAID arrays continuously without manual intervention.
What should I do when RAID array shows degraded status?
When RAID array shows degraded status, immediately identify the failed disk, verify disk failure, check remaining disk health, replace failed disk as soon as possible, and monitor rebuild progress closely. Degraded arrays have reduced redundancy and are vulnerable to additional disk failures.
Can I monitor RAID arrays without unmounting filesystems?
Yes, you can monitor RAID array status without unmounting filesystems using cat /proc/mdstat or mdadm --detail. RAID monitoring doesn't require unmounting. However, disk replacement and rebuild operations may require maintenance windows.
How do I identify which disk has failed in a RAID array?
Use mdadm --detail /dev/md0 for software RAID or hardware RAID controller tools to list disk status. Failed disks will show as "failed" or "removed" status. Check SMART status for disk health information. Zuzia.app tracks individual disk status automatically.
Why is monitoring RAID arrays important?
Monitoring RAID arrays helps detect disk failures early, prevent data loss, maintain storage redundancy, track rebuild progress, plan disk replacements proactively, and ensure reliable storage operations. RAID failures can cause data loss, so tracking RAID health is essential for maintaining data protection.
How do I compare RAID array health across multiple servers?
Use Zuzia.app to monitor RAID arrays across multiple servers simultaneously. Each server executes RAID checks independently, and all results are stored in Zuzia.app's database for centralized comparison and analysis. You can view RAID array health for all servers in a single dashboard and identify servers with RAID issues.
Does Zuzia.app track RAID array health changes over time?
Yes, Zuzia.app stores all command outputs in its database, allowing you to track RAID array health over time and identify when disk failures or array degradation occur. You can view historical data to see RAID health trends, identify disk failure patterns, and verify that disk replacements were successful. This helps you maintain RAID reliability and troubleshoot storage issues proactively.
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