Azure VM Availability Zone Migration Script

This script simplifies the process of migrating an Azure Virtual Machine (VM) from an Availability Set or a specific Availability Zone to another Availability Zone while maintaining the same VM name, resource group, network interface, and other configurations. The script leverages Azure Backup Vault for rollback safety and uses disk snapshots to ensure data integrity during migration.

Features

• Automatic Rollback Support: Creates an on-demand backup in the Azure Backup Vault for recovery.
• Snapshot-Based Migration: Utilizes snapshots for OS and data disks, ensuring seamless migration without data loss.
• Preserves Configuration: Retains the VM name, size, network interface, and tags.
• Zone Selection: Allows migration to a specified Availability Zone.
• Automated Cleanup: Removes old snapshots and disks after successful migration.

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Prerequisites

1. Azure CLI installed and authenticated. Install Azure CLI
2. A configured Azure Backup Vault for storing on-demand backups.
3. Sufficient permissions for managing Azure resources.

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Usage

Run the script with the following parameters:

./migrate-vm-az.sh \
  -g <resource-group> \
  -n <vm-name> \
  -z <new-availability-zone> \
  -l <location> \
  -v <backup-vault-name>

Parameters

• -g <resource-group>: Resource group of the VM.
• -n <vm-name>: Name of the VM to be migrated.
• -z <new-availability-zone>: Target Availability Zone (e.g., 1, 2, or 3).
• -l <location>: Azure region where the VM is located (e.g., eastus).
• -v <backup-vault-name>: Name of the Azure Backup Vault.

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Example

./migrate-vm-az.sh \
  -g my-resource-group \
  -n my-vm \
  -z 2 \
  -l eastus \
  -v my-backup-vault

This command migrates the VM my-vm in the my-resource-group to Availability Zone 2 within the eastus region, while creating an on-demand backup in the my-backup-vault.

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How It Works

1. Backup and Deallocation:
   • Stops the VM.
   • Initiates an on-demand backup in the specified Azure Backup Vault.
2. Snapshot Creation:
   • Creates snapshots of the OS and data disks.
3. Disk and VM Recreation:
   • Recreates the OS and data disks in the new Availability Zone.
   • Deletes the original VM and recreates it in the new Availability Zone with preserved configurations.
4. Cleanup:
   • Removes old disks and snapshots after a successful migration.

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Safety Measures

• The script halts on errors (set -e) to avoid partial execution.
• It verifies and waits for key operations (e.g., backup, snapshot creation) to complete before proceeding.
• Retains backups for 7 days in the Azure Backup Vault.

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Notes

• Ensure the Azure Backup Vault is set up correctly before running the script.
• The script cleans up old resources only if the migration is successful. Manual cleanup may be required in case of errors.
• Some VM configurations (e.g., ultra disks) might require additional setup.
• Limitation: This script does not support VMs using shared disks or VMs with public IPs.

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Contribution

Feel free to submit issues or improvements for the script! Contributions from the community are welcome to make this migration tool even more robust.

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Disclaimer: This script is provided as-is. Test it in a non-production environment before using it in production scenarios.

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License

This script is licensed under the MIT License. See the LICENSE file for details.

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Author

Developed by Jeanclei.

For questions or contributions, feel free to reach out!

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