Skip to content

vSAN Diagnostics Guide#

Overview#

The vSAN Diagnostics tool provides comprehensive storage system analysis and troubleshooting capabilities for VergeOS virtual Storage Area Networks. These diagnostic commands enable system administrators to monitor storage performance, troubleshoot storage issues, and maintain optimal vSAN health across the entire cluster.

What You'll Learn

  • How to access and use vSAN diagnostic tools
  • Understanding of each diagnostic command and its storage focus
  • Best practices for vSAN troubleshooting and maintenance
  • When to use specific diagnostic commands for storage issues

Prerequisites#

  • Access to VergeOS interface with vSAN management privileges
  • Basic understanding of distributed storage concepts
  • Knowledge of VergeOS vSAN architecture

vSAN Access

vSAN diagnostics are only available at the root/parent level. Tenants do not have access to vSAN diagnostic tools.

Accessing vSAN Diagnostics#

  1. Navigate to vSAN Diagnostics: - From the Main Dashboard, click System in the left menu - Click vSAN Diagnostics in the left menu - Or alternatively: Click the vSAN Tiers count box → vSAN Diagnostics

  2. Using Diagnostic Commands: - Select desired command from the Query dropdown menu - Configure available parameters on the right side - Click Send → to execute the command

Command Visibility

Enable "Show Command" to view the exact command being executed, useful for SSH execution or script automation.

Diagnostic Commands Reference#

Find Inode#

Purpose: Locates specific inodes within the vSAN file system for detailed analysis.

When to Use: - Troubleshooting file system corruption - Locating specific data blocks - Advanced storage troubleshooting

Parameters: - Inode Number: Specific inode identifier to locate

CLI Syntax:

vcmd find --inode=[INODE_NUMBER]


Get Cache Info#

Purpose: Displays comprehensive caching system information and statistics.

When to Use: - Performance optimization - Cache hit/miss ratio analysis - Memory usage assessment - Storage performance troubleshooting

CLI Syntax:

vcmd cache info


Get Clients#

Purpose: Shows active vSAN clients and their connection details.

When to Use: - Connection troubleshooting - Client performance analysis - Network connectivity verification - Load distribution assessment

CLI Syntax:

vcmd clients list


Get Cluster Rates#

Purpose: Displays cluster-wide performance metrics and throughput rates.

When to Use: - Cluster performance monitoring - Throughput analysis - Performance baseline establishment - Capacity planning

CLI Syntax:

vcmd cluster rates


Get Cluster Usage#

Purpose: Shows comprehensive cluster storage utilization statistics.

When to Use: - Capacity planning - Storage utilization monitoring - Space allocation analysis - Growth trend assessment

CLI Syntax:

vcmd cluster usage


Get Current Master#

Purpose: Identifies the current vSAN master node in the cluster.

When to Use: - Cluster leadership troubleshooting - Master failover analysis - Cluster coordination issues - Performance optimization

CLI Syntax:

vcmd master current


Get Device List#

Purpose: Lists all storage devices participating in the vSAN.

When to Use: - Device inventory management - Storage configuration verification - Device status monitoring - Capacity assessment

CLI Syntax:

vcmd devices list


Get Device Status#

Purpose: Displays detailed status information for vSAN storage devices.

When to Use: - Device health monitoring - Failure detection - Performance analysis - Maintenance planning

Parameters: - Device ID: Specific device to query

CLI Syntax:

vcmd device status [DEVICE_ID]


Get Device Usage#

Purpose: Shows usage statistics for individual storage devices.

When to Use: - Device utilization monitoring - Load balancing analysis - Performance optimization - Wear leveling assessment

Parameters: - Device ID: Target device for analysis

CLI Syntax:

vcmd device usage [DEVICE_ID]


Get File Status#

Purpose: Retrieves detailed status information for specific files in vSAN.

When to Use: - File integrity verification - Replication status checking - Data location tracking - Corruption investigation

Parameters: - File Path: Target file for analysis

CLI Syntax:

vcmd file status [FILE_PATH]


Get Fuse Info#

Purpose: Displays FUSE (Filesystem in Userspace) mount and operation information.

When to Use: - File system mount troubleshooting - FUSE performance analysis - Mount point verification - Access issue diagnosis

CLI Syntax:

vcmd fuse info


Get Integ Check Status#

Purpose: Shows the status of ongoing or completed integrity check operations.

When to Use: - Data integrity monitoring - Verification process tracking - Corruption detection - Maintenance status checking

CLI Syntax:

vcmd integcheck status


Get Journal Status#

Purpose: Displays vSAN journal status and operation information.

When to Use: - Write performance troubleshooting - Journal space monitoring - Transaction logging analysis - Performance optimization

CLI Syntax:

vcmd journal status


Get Node Device List#

Purpose: Lists storage devices for specific nodes in the cluster.

When to Use: - Node-specific device inventory - Per-node capacity planning - Device distribution analysis - Node maintenance preparation

Parameters: - Node ID: Target node for device listing

CLI Syntax:

vcmd node devices [NODE_ID]


Get Node Info#

Purpose: Displays comprehensive information about specific vSAN nodes.

When to Use: - Node health assessment - Configuration verification - Performance analysis - Troubleshooting node issues

Parameters: - Node ID: Target node identifier

CLI Syntax:

vcmd node info [NODE_ID]


Get Node List#

Purpose: Lists all nodes participating in the vSAN cluster.

When to Use: - Cluster membership verification - Node inventory management - Cluster topology analysis - Health status overview

CLI Syntax:

vcmd nodes list


Get Path from Inode#

Purpose: Resolves file system paths from inode numbers.

When to Use: - File system navigation - Inode-to-path mapping - Corruption analysis - Advanced troubleshooting

Parameters: - Inode Number: Source inode for path resolution

CLI Syntax:

vcmd path from-inode [INODE_NUMBER]


Get Read Ahead#

Purpose: Shows read-ahead caching configuration and statistics.

When to Use: - Read performance optimization - Cache tuning - Sequential access analysis - Performance troubleshooting

CLI Syntax:

vcmd readahead status


Get Repair Status#

Purpose: Displays status of ongoing repair operations and data reconstruction.

When to Use: - Data repair monitoring - Recovery process tracking - Failure recovery assessment - Maintenance status checking

CLI Syntax:

vcmd repair status


Get Running Conf#

Purpose: Shows the current running configuration of the vSAN system.

When to Use: - Configuration verification - Troubleshooting configuration issues - Backup configuration reference - Change management

CLI Syntax:

vcmd config show


Get Sync List#

Purpose: Lists synchronization operations and their status.

When to Use: - Data synchronization monitoring - Replication status tracking - Consistency verification - Performance analysis

CLI Syntax:

vcmd sync list


Get Tier Device Maps#

Purpose: Shows device mapping across different storage tiers.

When to Use: - Tier configuration verification - Device placement analysis - Performance optimization - Capacity planning

CLI Syntax:

vcmd tier device-maps


Get Tier Node Maps#

Purpose: Displays how storage tiers are distributed across cluster nodes.

When to Use: - Tier distribution analysis - Load balancing verification - Performance optimization - Capacity planning

CLI Syntax:

vcmd tier node-maps


Get Tier Status#

Purpose: Shows comprehensive status information for storage tiers.

When to Use: - Tier health monitoring - Performance analysis - Capacity utilization tracking - Tier optimization

CLI Syntax:

vcmd tier status


Get Top Usage Rates#

Purpose: Identifies top consumers of storage resources and performance.

When to Use: - Performance bottleneck identification - Resource utilization analysis - Capacity planning - Usage optimization

CLI Syntax:

vcmd usage top-rates


Get Usage#

Purpose: Displays comprehensive vSAN usage statistics and metrics.

When to Use: - Overall system utilization monitoring - Capacity planning - Performance baseline establishment - Resource allocation analysis

CLI Syntax:

vcmd usage show


Get Volume Usage#

Purpose: Shows usage statistics for individual volumes within vSAN.

When to Use: - Volume-specific capacity monitoring - Performance analysis - Space allocation verification - Growth tracking

Parameters: - Volume ID: Target volume for analysis

CLI Syntax:

vcmd volume usage [VOLUME_ID]


Integ Check#

Purpose: Initiates comprehensive data integrity checking across the vSAN.

When to Use: - Scheduled maintenance - Data corruption investigation - Preventive health checks - Post-failure verification

Performance Impact

Integrity checks can significantly impact system performance and should be scheduled during maintenance windows.

CLI Syntax:

vcmd integcheck start


Integ Check Device#

Purpose: Performs integrity checking on specific storage devices.

When to Use: - Device-specific integrity verification - Targeted troubleshooting - Post-repair verification - Selective maintenance

Parameters: - Device ID: Target device for integrity check

CLI Syntax:

vcmd integcheck device [DEVICE_ID]


Summarize Disk Usage#

Purpose: Provides comprehensive disk usage summary across the entire vSAN.

When to Use: - Capacity reporting - Usage trend analysis - Storage optimization planning - Executive reporting

CLI Syntax:

vcmd usage summarize

Best Practices#

vSAN Health Monitoring Workflow#

  1. System Overview: Start with Get Cluster Usage and Get Cluster Rates
  2. Performance Analysis: Review Get Top Usage Rates and device-specific metrics
  3. Health Assessment: Check Get Repair Status and Get Integ Check Status
  4. Capacity Planning: Use Summarize Disk Usage and tier information
  5. Troubleshooting: Employ device-specific and node-specific commands as needed

Preventive Maintenance#

  • Regular Health Checks: Monitor cluster usage, repair status, and device health
  • Performance Monitoring: Track cluster rates and top usage patterns
  • Integrity Verification: Schedule periodic integrity checks during maintenance windows
  • Capacity Planning: Regularly review usage trends and growth patterns

Performance Optimization#

  • Cache Analysis: Monitor cache info and hit ratios for optimization opportunities
  • Tier Management: Review tier device maps and node maps for balanced distribution
  • Load Balancing: Use client and usage information to optimize workload distribution
  • Read Optimization: Tune read-ahead settings based on access patterns

Troubleshooting Common vSAN Issues#

Performance Problems#

  1. Check Get Cluster Rates and Get Top Usage Rates for bottlenecks
  2. Review Get Cache Info for cache efficiency
  3. Analyze Get Device Usage for individual device performance

Capacity Issues#

  1. Use Get Cluster Usage and Summarize Disk Usage for space analysis
  2. Review Get Tier Status for tier-specific capacity
  3. Check Get Volume Usage for individual volume consumption

Data Integrity Concerns#

  1. Review Get Integ Check Status for recent integrity checks
  2. Check Get Repair Status for ongoing repairs
  3. Use Get File Status for specific file integrity verification

Cluster Health Issues#

  1. Verify Get Current Master for leadership status
  2. Check Get Node List and Get Node Info for node health
  3. Review Get Sync List for synchronization issues

Device Problems#

  1. Use Get Device List and Get Device Status for device health
  2. Check Get Node Device List for node-specific device issues
  3. Run Integ Check Device for suspected device problems

Advanced Diagnostics#

File System Analysis#

  • Use Find Inode and Get Path from Inode for file system investigation
  • Employ Get File Status for detailed file analysis
  • Check Get Fuse Info for mount-related issues

Configuration Management#

  • Review Get Running Conf for current configuration
  • Verify tier and device mappings with mapping commands
  • Cross-reference node and device information for consistency

Performance Tuning#

  • Analyze cache and read-ahead statistics for optimization
  • Monitor client connections and usage patterns
  • Review journal status for write performance optimization

Next Steps#

After mastering vSAN diagnostics, consider exploring:

  • Advanced vSAN performance tuning techniques
  • Automated monitoring and alerting systems
  • Integration with external storage management tools
  • Disaster recovery and backup strategies

For complex vSAN issues or performance optimization guidance, contact VergeOS Support with detailed diagnostic output and system configuration information.