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Cloning VMs

Duplicate VMs with their home directory contents for parallel work, testing, or team onboarding.

Quick Start

# Clone single VM
azlin clone my-vm

# Clone with custom session name
azlin clone my-vm --session-prefix dev-env

# Create multiple clones
azlin clone my-vm --num-replicas 3 --session-prefix worker

Overview

The azlin clone command creates new VMs based on an existing VM with:

  • Home directory copy - All files, code, and configurations
  • Security filtering - Excludes SSH keys, credentials, tokens
  • Parallel creation - Clone multiple VMs simultaneously
  • Custom sizing - Override VM size for clones
  • Session naming - Auto-generate meaningful session names

Command Reference

azlin clone [OPTIONS] SOURCE_VM

Arguments

Argument Description Required
SOURCE_VM VM name or session name to clone Yes

Options

Option Description Default
--num-replicas INTEGER Number of clones to create 1
--session-prefix TEXT Session name prefix for clones None
--resource-group, --rg TEXT Resource group From config
--vm-size TEXT VM size for clones Same as source
--region TEXT Azure region Same as source

Common Usage Patterns

Single Clone

# Clone VM with default name
azlin clone my-dev-vm

# Creates: my-dev-vm-clone-1 (or similar)

What happens:

  1. Creates new VM with same specs as source
  2. Copies /home/azureuser from source to clone
  3. Filters out sensitive files (SSH keys, .env, etc.)
  4. VM ready to use immediately

Clone with Session Name

# Clone and assign session name
azlin clone my-dev-vm --session-prefix backend-api

# Creates VM with session: backend-api

What happens:

  1. Creates clone as normal
  2. Sets session name to backend-api
  3. Can connect with: azlin connect backend-api

Multiple Clones (Replicas)

# Create 3 identical VMs
azlin clone my-vm --num-replicas 3 --session-prefix worker

# Creates:
#   - worker-1
#   - worker-2
#   - worker-3

What happens:

  1. Provisions 3 VMs in parallel
  2. Each gets sequentially numbered session name
  3. All share the same home directory contents (copied)
  4. Perfect for distributed workloads

Clone with Different Size

# Clone to larger VM
azlin clone dev-vm --vm-size Standard_E64s_v5 --session-prefix training

# Clone to smaller VM (for testing)
azlin clone ml-vm --vm-size Standard_D4s_v3 --session-prefix test

Clone by Session Name

# Set session on source VM
azlin session azlin-vm-12345 my-project

# Clone using session name
azlin clone my-project --session-prefix my-project-test

Use Cases

Parallel Development

# Create environment for each developer
azlin clone shared-dev-vm --num-replicas 5 --session-prefix dev
# Creates: dev-1, dev-2, dev-3, dev-4, dev-5

# Each developer connects to their own
azlin connect dev-1  # Sarah
azlin connect dev-2  # John
azlin connect dev-3  # Maria

Testing/QA

# Clone production-like environment for testing
azlin clone prod-vm --session-prefix qa-test --vm-size Standard_D16s_v3

# Run tests without affecting prod
azlin connect qa-test -- pytest tests/

Training/Education

# Clone instructor environment for students
azlin clone instructor-vm --num-replicas 20 --session-prefix student
# Creates: student-1, student-2, ..., student-20

# Each student gets identical setup

Distributed Computing

# Clone for parallel processing
azlin clone base-worker --num-replicas 10 --session-prefix worker

# Each worker processes different data
azlin connect worker-1 -- python process.py --shard 1
azlin connect worker-2 -- python process.py --shard 2
# ...

A/B Testing

# Clone for experimental features
azlin clone stable-vm --session-prefix experimental

# Test changes without affecting stable
azlin connect experimental
# Make changes, test, compare results

What Gets Copied

Included

  • All files in /home/azureuser
  • Code repositories
  • Configuration files (non-sensitive)
  • Docker images and containers
  • Installed Python packages
  • Project dependencies

Excluded (Security Filters)

  • SSH keys (~/.ssh/id_*)
  • Environment files (.env, .env.*)
  • Credential files (credentials.json, etc.)
  • API tokens and secrets
  • Azure CLI credentials (~/.azure)
  • Git credentials cache

Fresh Credentials

Clones get fresh SSH keys from Azure Key Vault automatically. You'll need to re-configure any API keys or tokens.

Performance

Timing

  • Single clone: 10-15 minutes
  • Multiple clones: Same (parallel provisioning)
  • Home copy: 1-5 minutes (depends on size)

Optimization

# Faster cloning - clean up source first
azlin connect source-vm -- "
  docker system prune -af
  rm -rf ~/.cache
  uv cache clean
"

azlin clone source-vm --num-replicas 5

Advanced Scenarios

Cross-Region Cloning

# Clone to different region
azlin clone eastus-vm --region westus --session-prefix westus-clone

Custom Resource Group

# Clone to different resource group
azlin clone my-vm --rg production-rg --session-prefix prod-clone

Batch Clone Script

#!/bin/bash
# Create clones for entire team

TEAM=(alice bob carol dave)
for member in "${TEAM[@]}"; do
  azlin clone shared-dev --session-prefix "dev-$member"
done

Troubleshooting

Clone Fails to Provision

# Check quota
azlin quota

# Try smaller VM size
azlin clone my-vm --vm-size Standard_D4s_v3

# Try different region
azlin clone my-vm --region westus

Home Directory Too Large

# Clean up source VM first
azlin connect source-vm -- "
  docker system prune -af
  rm -rf ~/.cache ~/.npm ~/.cargo/registry
"

# Then clone
azlin clone source-vm

Missing Files After Clone

# Check security filters
# Sensitive files are intentionally excluded

# Manually copy if needed (after verifying safety)
azlin connect source-vm -- tar czf /tmp/extra.tar.gz ~/specific-files
azlin connect clone-vm -- "cd ~ && tar xzf -" < /tmp/extra.tar.gz

Clones Have Same Name

# Always use --session-prefix for clarity
azlin clone source --session-prefix unique-name-1
azlin clone source --session-prefix unique-name-2

Cleanup

Delete Single Clone

azlin delete clone-vm

Delete Multiple Clones

# Delete all worker clones
for i in {1..10}; do
  azlin delete worker-$i
done

# Or use Azure CLI for batch deletion
az vm delete --ids $(az vm list -g <rg> --query "[?contains(name, 'worker')].id" -o tsv) --yes

Source Code

Last updated: 2025-11-24