Skip to content

azlin snapshot restore

Restore a VM from a snapshot, replacing the current OS disk.

Description

Restores a VM to a previous state by replacing its OS disk with one created from a snapshot. WARNING: This operation is destructive - all current data on the VM will be lost.

Usage

azlin snapshot restore VM_NAME SNAPSHOT_NAME [OPTIONS]

Arguments

  • VM_NAME - Name of the VM to restore
  • SNAPSHOT_NAME - Name of the snapshot to restore from

Options

Option Description
--force Skip confirmation prompt
--resource-group, --rg TEXT Azure resource group
-h, --help Show help message

Examples

Basic Restore

azlin snapshot restore my-vm my-vm-snapshot-20251124-143022

Output: 

⚠ WARNING: This will replace the current OS disk!

VM: my-vm
Current Disk: my-vm-osdisk (30 GB)
Snapshot: my-vm-snapshot-20251124-143022 (30 GB, created 2025-11-24 14:30)

ALL CURRENT DATA WILL BE LOST

Type 'RESTORE' to confirm: RESTORE

Stopping VM...
Creating disk from snapshot...
Detaching current disk...
Attaching restored disk...
Starting VM...

Restore complete! VM is starting up.
SSH will be available in ~30 seconds.

Force Restore (No Prompt)

azlin snapshot restore my-vm my-vm-snapshot-20251124-143022 --force

Restore After Failed Update

# Update failed, need to rollback
azlin snapshot list my-vm
# Find snapshot from before update
azlin snapshot restore my-vm my-vm-snapshot-20251124-120000

Common Use Cases

Rollback Failed Deployment

# Deployment broke production
azlin snapshot restore prod-api prod-api-snapshot-20251124-020000

# Verify restoration
azlin connect prod-api
# Check app is working

Recover from Misconfiguration

# Accidentally deleted important files
azlin snapshot restore my-vm my-vm-snapshot-20251123-235959

# SSH back in
azlin connect my-vm
# Files are restored

Experiment Cleanup

# Tried experimental changes, want clean slate
azlin snapshot restore experiment-vm experiment-vm-snapshot-20251124-100000

What Happens During Restore

  1. VM Stopped: VM is deallocated
  2. Disk Created: New disk created from snapshot
  3. Swap Disks: Current disk detached, new disk attached
  4. VM Started: VM boots from restored disk
  5. Old Disk: Previous disk is kept as backup (deleted after 7 days)

Duration: 5-15 minutes depending on disk size

Important Notes

Data Loss

  • Current disk data is LOST
  • Create a snapshot before restore if you need current data
  • Old disk is temporarily kept but will be deleted

Downtime

  • VM must be stopped during restore
  • Expect 5-15 minutes of downtime
  • Plan restores during maintenance windows

Saved Backup Disk

The replaced disk is saved temporarily as {vm-name}-osdisk-backup-{timestamp} for 7 days, allowing recovery if restore was mistake.

Troubleshooting

Restore Failed - Disk Size Mismatch

Error: "Snapshot disk size doesn't match VM"

Solution: This shouldn't happen with azlin snapshots, but if it does: 

# Check snapshot details
azlin snapshot list my-vm

# Contact support if size mismatch occurs

VM Won't Start After Restore

Issue: VM restored but won't boot

Solution: 

# Check VM status
azlin list --vm my-vm

# View boot diagnostics
az vm boot-diagnostics get-boot-log --name my-vm --resource-group azlin-rg

# If corrupt, restore from different snapshot
azlin snapshot restore my-vm my-vm-snapshot-{earlier-date}

Best Practices

Always Have Recent Snapshot

# Before risky operations
azlin snapshot create my-vm

# Perform operation
# ...

# Restore if needed
azlin snapshot restore my-vm {snapshot-name}

Test Restores

Periodically test that snapshots can be restored:

# Clone VM for testing
azlin clone my-vm --name restore-test

# Restore clone from snapshot
azlin snapshot restore restore-test {snapshot-name}

# Verify works
azlin connect restore-test

# Clean up
azlin destroy restore-test

Document Snapshots

Know what each snapshot contains:

# Keep external notes
echo "my-vm-snapshot-20251124-143022: Pre-Python 3.13 upgrade" >> snapshots.txt

See Also