Disk Management

Zorvia provides comprehensive disk management capabilities for KubeVirt VMs, including PVC expansion, health monitoring, and automated filesystem resizing.

Features

1. Disk Expansion (disk-expand)

Expand VM disks seamlessly with integrated PVC resizing and filesystem expansion.

Usage:

# Expand a disk to 100Gi
zorvia disk-expand my-vm root 100Gi

# Show expansion plan without executing
zorvia disk-expand my-vm root 100Gi --plan

# Specify custom PVC name
zorvia disk-expand my-vm root 100Gi --pvc my-custom-pvc

Features:

• PVC resizing in Kubernetes
• Step-by-step expansion plan
• Progress tracking
• Automatic verification
• Support for multiple storage classes

Expansion Steps:

1. Resize PVC in Kubernetes
2. Rescan disk in VM
3. Extend physical volume (if using LVM)
4. Extend logical volume
5. Resize filesystem

2. Disk Health Checks (disk-health)

Monitor disk usage and get alerts when disks need attention.

Usage:

# Quick health check
zorvia disk-health my-vm

# Detailed disk information
zorvia disk-health my-vm --detailed

Health Status Levels:

• Healthy: < 75% usage (green ✓)
• Warning: 75-89% usage (yellow ⚠)
• Critical: 90-97% usage (red ✗)
• Full: ≥ 98% usage (red ✗)

Features:

• Real-time disk usage monitoring
• Automatic health status detection
• Expansion recommendations
• Configurable thresholds
• Alert generation

Example Output:

╭─────────────────────────────────────╮
│  Disk Health: my-vm                 │
╰─────────────────────────────────────╯

Overall Status: ⚠ WARNING

Disk Details:
  ✓ /
    Size:       100Gi
    Used:       75Gi (75.0%)
    Available:  25Gi
    Filesystem: ext4
    Device:     /dev/vda1

  ✗ /data
    Size:       200Gi
    Used:       180Gi (90.0%)
    Available:  20Gi
    Filesystem: xfs
    Device:     /dev/vdb1
    → Recommended size: 180Gi

Alerts:
  ⚠ Disk /data usage is high (90.0% used, 20Gi available)
    Consider expanding disk or cleaning up unused data

ℹ Use 'zorvia disk-expand' to expand disks

3. Expansion Scripts (disk-script)

Generate automated filesystem expansion scripts for different configurations.

Usage:

# Generate script for LVM with ext4
zorvia disk-script --filesystem lvm --device /dev/vda

# Generate script for XFS on LVM
zorvia disk-script --filesystem lvm-xfs --device /dev/vda

# Generate script for direct ext4 partition
zorvia disk-script --filesystem ext4 --device /dev/sda

# Save to file
zorvia disk-script --filesystem lvm --device /dev/vda --output expand.sh

# Generate dry-run script
zorvia disk-script --filesystem lvm --device /dev/vda --dry-run

Supported Filesystems:

• ext4 - Direct ext4 partition
• xfs - Direct XFS partition
• btrfs - Btrfs filesystem
• lvm or lvm-ext4 - LVM with ext4
• lvm-xfs - LVM with XFS

Script Features:

• Root permission checks
• Disk rescan automation
• Partition growth (growpart)
• LVM expansion (pvresize, lvextend)
• Filesystem resizing (resize2fs, xfs_growfs)
• Pre and post verification
• Dry-run mode for testing

Example Generated Script:

#!/bin/bash
# Automated Filesystem Expansion Script
# Generated by Zorvia

set -e  # Exit on error

echo "=== Pre-Flight Checks ==="

# Check if running as root
if [ "$EUID" -ne 0 ]; then
    echo "Error: This script must be run as root"
    exit 1
fi

echo "=== Rescanning disk: /dev/vda ==="
echo 1 | tee /sys/class/block/vda/device/rescan
sleep 2

echo "=== LVM Expansion ==="
pvresize /dev/vda3
lvextend -l +100%FREE /dev/mapper/vg-root
resize2fs /dev/mapper/vg-root

echo "=== Verification ==="
df -h
lsblk

One-Liner Commands:

The tool also generates convenient one-liner commands:

# LVM with ext4
echo 1 | sudo tee /sys/class/block/vda/device/rescan && \
sudo pvresize /dev/vda3 && \
sudo lvextend -l +100%FREE /dev/mapper/vg-root && \
sudo resize2fs /dev/mapper/vg-root

# Direct ext4 partition
echo 1 | sudo tee /sys/class/block/sda/device/rescan && \
sudo growpart /dev/sda 1 && \
sudo resize2fs /dev/sda1

# XFS on LVM
echo 1 | sudo tee /sys/class/block/vda/device/rescan && \
sudo pvresize /dev/vda3 && \
sudo lvextend -l +100%FREE /dev/mapper/vg-root && \
sudo xfs_growfs /

4. Disk Usage Statistics (disk-usage)

View disk usage statistics across VMs.

Usage:

# Show usage for all VMs
zorvia disk-usage

# Show usage for specific VM
zorvia disk-usage --vm my-vm

# Sort by usage percentage
zorvia disk-usage --sort-by usage

# Sort by size
zorvia disk-usage --sort-by size

# JSON output
zorvia disk-usage --output json

Sort Options:

• name - Sort by VM/disk name (default)
• usage - Sort by usage percentage
• size - Sort by total size
• available - Sort by available space

Output Formats:

• table - Formatted table (default)
• json - JSON format
• yaml - YAML format

Configuration

Health Check Thresholds

Customize health check thresholds in your code:

use disk::{DiskHealthConfig, DiskHealthCheck};

let config = DiskHealthConfig {
    warning_threshold: 70.0,   // Default: 75.0
    critical_threshold: 85.0,  // Default: 90.0
    full_threshold: 95.0,      // Default: 98.0
    min_free_space_gb: 10.0,   // Default: 5.0
};

let checker = DiskHealthCheck::new(config);

Expansion Configuration

use disk::{DiskConfig, DiskExpansion};

let config = DiskConfig::new("root", "my-pvc")
    .with_sizes("50Gi", "100Gi");

let expansion = DiskExpansion::new("default");
let plan = expansion.create_plan("my-vm", &config)?;

Integration with KubeVirt

PVC Expansion Requirements

1. StorageClass Configuration:

   apiVersion: storage.k8s.io/v1
   kind: StorageClass
   metadata:
     name: expandable-storage
   provisioner: kubernetes.io/cinder
   allowVolumeExpansion: true  # Required for expansion

2. PVC Expansion:

   # Zorvia handles this automatically
   zorvia disk-expand my-vm root 100Gi
   
   # Or manually with kubectl
   kubectl patch pvc my-pvc -p '{"spec":{"resources":{"requests":{"storage":"100Gi"}}}}'

3. Filesystem Expansion in VM:

   # Generate and run expansion script
   zorvia disk-script --filesystem lvm --device /dev/vda --output expand.sh
   chmod +x expand.sh
   sudo ./expand.sh

Workflow

graph TD
    A[Check Disk Health] --> B{Needs Expansion?}
    B -->|Yes| C[Create Expansion Plan]
    B -->|No| D[Monitor]
    C --> E[Resize PVC in K8s]
    E --> F[Wait for PVC Ready]
    F --> G[Rescan Disk in VM]
    G --> H[Run Expansion Script]
    H --> I[Verify Expansion]
    I --> J[Complete]
    D --> A

Best Practices

1. Regular Health Checks

Schedule regular disk health checks:

# Check daily with cron
0 9 * * * zorvia disk-health my-vm --detailed | mail -s "VM Disk Health" admin@example.com

2. Proactive Expansion

Expand disks before they reach critical levels:

# Check and expand if needed
if zorvia disk-health my-vm | grep -q "WARNING\|CRITICAL"; then
    zorvia disk-expand my-vm root 100Gi
fi

3. Test Expansion Scripts

Always test expansion scripts in dry-run mode first:

# Generate dry-run script
zorvia disk-script --filesystem lvm --device /dev/vda --dry-run > test-expand.sh

# Review the script
cat test-expand.sh

# Run in dry-run mode
chmod +x test-expand.sh
sudo ./test-expand.sh

4. Backup Before Expansion

Create a snapshot before expanding critical disks:

# Create snapshot
zorvia snapshot-create my-vm --name pre-expansion-backup

# Expand disk
zorvia disk-expand my-vm root 100Gi

# Verify and delete snapshot if successful
zorvia snapshot-delete pre-expansion-backup

5. Monitor After Expansion

Verify successful expansion:

# Check health after expansion
zorvia disk-health my-vm --detailed

# Verify filesystem size
df -h

# Check PVC status
kubectl get pvc -n default

Troubleshooting

PVC Expansion Stuck

Problem: PVC remains in "Resizing" state

Solution:

# Check PVC conditions
kubectl describe pvc my-pvc

# Check if VM is running (some storage requires VM restart)
zorvia restart my-vm

# Force rescan
kubectl delete pod -l kubevirt.io/vm=my-vm

Filesystem Not Expanding

Problem: PVC expanded but filesystem size unchanged

Solution:

# Check if VM sees new size
lsblk

# Rescan disk manually
echo 1 | sudo tee /sys/class/block/vda/device/rescan

# Run expansion script
zorvia disk-script --filesystem lvm --device /dev/vda --output expand.sh
chmod +x expand.sh
sudo ./expand.sh

LVM Not Detecting New Space

Problem: pvresize fails or doesn't detect new space

Solution:

# Rescan SCSI bus
echo "- - -" | sudo tee /sys/class/scsi_host/host*/scan

# Check partition table
sudo fdisk -l /dev/vda

# Extend partition first
sudo growpart /dev/vda 3

# Then resize PV
sudo pvresize /dev/vda3

StorageClass Doesn't Support Expansion

Problem: StorageClass has allowVolumeExpansion: false

Solution:

# Create new StorageClass with expansion enabled
cat <<EOF | kubectl apply -f -
apiVersion: storage.k8s.io/v1
kind: StorageClass
metadata:
  name: expandable-storage
provisioner: $(kubectl get sc <old-sc> -o jsonpath='{.provisioner}')
allowVolumeExpansion: true
parameters:
  # Copy parameters from old StorageClass
EOF

# Create new PVC with expandable StorageClass
# Migrate data and update VM spec

Advanced Usage

Custom Expansion Plans

use disk::{ExpansionPlan, ExpansionStep};

let mut plan = ExpansionPlan::new("my-vm", &config);

// Add custom step
plan.steps.push(ExpansionStep {
    step_number: 6,
    description: "Notify monitoring system".to_string(),
    command: "curl -X POST https://monitoring.example.com/notify".to_string(),
    completed: false,
});

Batch Disk Expansion

# Expand all disks in namespace
for vm in $(zorvia list --output json | jq -r '.[].name'); do
    echo "Checking $vm..."
    if zorvia disk-health $vm | grep -q "WARNING\|CRITICAL"; then
        echo "Expanding $vm..."
        zorvia disk-expand $vm root 100Gi
    fi
done

Integration with Monitoring

# Export metrics for Prometheus
zorvia disk-usage --output json | jq -r '.[] |
    "disk_usage{vm=\"\(.vm)\",mount=\"\(.mount)\"} \(.usage_percent)"'

API Reference

DiskInfo

pub struct DiskInfo {
    pub name: String,
    pub mount_point: String,
    pub size: String,
    pub used: String,
    pub available: String,
    pub usage_percent: f64,
    pub filesystem: String,
    pub device: String,
}

impl DiskInfo {
    pub fn parse_size(size_str: &str) -> u64
    pub fn format_size(bytes: u64) -> String
    pub fn needs_expansion(&self, threshold: f64) -> bool
}

DiskHealthCheck

pub struct DiskHealthCheck {
    config: DiskHealthConfig,
}

impl DiskHealthCheck {
    pub fn with_defaults() -> Self
    pub fn check_disk(&self, disk: &DiskInfo) -> DiskHealthStatus
    pub fn check_vm(&self, vm_name: &str, disks: Vec<DiskInfo>) -> DiskHealth
    pub fn recommend_expansion_size(&self, disk: &DiskInfo, target_usage: f64) -> String
}

ExpansionPlan

pub struct ExpansionPlan {
    pub vm_name: String,
    pub disk_name: String,
    pub current_size: String,
    pub target_size: String,
    pub steps: Vec<ExpansionStep>,
    pub status: ExpansionStatus,
}

impl ExpansionPlan {
    pub fn complete_step(&mut self, step_number: usize)
    pub fn next_step(&self) -> Option<&ExpansionStep>
    pub fn progress(&self) -> u8
}

ScriptGenerator

pub struct ScriptGenerator;

impl ScriptGenerator {
    pub fn generate(config: &ExpansionScript) -> String
    pub fn generate_oneliner(filesystem_type: &FilesystemType, device: &str) -> String
}

Examples

See examples/ directory for complete examples:

• disk-expansion-workflow.sh
• health-monitoring.sh
• automated-expansion.sh

Related

• GOLDEN_IMAGES.md — CDI golden / containerdisk sources
• SNAPSHOTS.md — snapshot before expansion windows
• WEB_CONSOLE.md — Fabric API day-2
• README.md