# Migrating VMware ESXi Workloads to OpenStack Using MigrateKit This guide describes a **practical, production-tested workflow** to migrate virtual machines from **VMware ESXi to OpenStack** using **MigrateKit** — an open-source migration tool developed by VEXXHOST. The approach focuses on: * Near-zero downtime * Full data integrity * Repeatable and automated execution --- ## Objectives * Migrate virtual machines from VMware ESXi to OpenStack * Minimize service downtime (typically 5–10 minutes) * Preserve data integrity * Enable repeatable and automated migration runs --- ## Architecture Overview ![](https://cdn.hashnode.com/res/hashnode/image/upload/v1767687108801/d363d98b-b9ac-4fb0-9af3-8dff78a8bab1.png align="center") --- ## Prerequisites ### MigrateKit Server * OS: Ubuntu 22.04 LTS * Memory: minimum 4 GB * Disk: minimum 50 GB * Network access to both VMware and OpenStack endpoints ### VMware VDDK * Version: 8.0.3 or later * Download from VMware Developer Portal ### Source Environment (VMware) * ESXi 6.7+ or vCenter-managed environment * Change Block Tracking (CBT) must be enabled ### Target Environment (OpenStack) * OpenStack Bobcat (2023.2) or later * Required services: Cinder, Nova, Neutron --- ## Part 1: MigrateKit Server Setup ### Install Docker ```bash sudo apt update && sudo apt upgrade -y curl -fsSL https://get.docker.com -o get-docker.sh sudo sh get-docker.sh docker --version ``` ### Install VMware VDDK ```bash scp VMware-vix-disklib-8.0.3-*.tar.gz root@migratekit:/tmp/ ssh root@migratekit cd /tmp tar -xzf VMware-vix-disklib-8.0.3-*.tar.gz sudo mkdir -p /usr/lib64/vmware-vix-disklib sudo cp -r vmware-vix-disklib-distrib/lib64/* /usr/lib64/vmware-vix-disklib/ ls -la /usr/lib64/vmware-vix-disklib/ ``` ### Configure OpenStack Credentials ```bash cat > ~/openstack-credentials.env << 'EOF' export OS_AUTH_URL=https://your-openstack.com:5000 export OS_PROJECT_NAME=your-project export OS_PROJECT_ID=your-project-id export OS_USERNAME=your-username export OS_PASSWORD=your-password export OS_REGION_NAME=RegionOne export OS_INTERFACE=public export OS_IDENTITY_API_VERSION=3 export OS_USER_DOMAIN_NAME=default export OS_PROJECT_DOMAIN_NAME=default EOF source ~/openstack-credentials.env ``` Validate connectivity: ```bash docker run --rm \ --env-file <(env | grep OS_) \ python:3-slim bash -c \ "pip install python-openstackclient && openstack token issue" ``` --- ## Part 2: Preparing the VMware Source ### Enable Change Block Tracking (CBT) ```bash ssh root@esxi-host vim-cmd vmsvc/getallvms | grep your-vm-name vim-cmd vmsvc/power.off vi /vmfs/volumes/datastore1/your-vm/your-vm.vmx # Add: ctkEnabled = "TRUE" scsi0:0.ctkEnabled = "TRUE" vim-cmd vmsvc/reload vim-cmd vmsvc/power.on ``` --- ## Part 3: Migration Workflow ### Phase 1: Initial Full Sync ```bash docker run -it --rm --privileged \ --network host \ -v /dev:/dev \ -v /usr/lib64/vmware-vix-disklib/:/usr/lib64/vmware-vix-disklib:ro \ --env-file <(env | grep OS_) \ ghcr.io/vexxhost/migratekit:main \ migrate \ --vmware-endpoint \ --vmware-username root \ --vmware-password "" \ --vmware-path /ha-datacenter/vm/ \ --debug ``` Expected output: ```plaintext INFO[0001] Creating snapshot INFO[0003] Volume created and set bootable Full copy 100% (25 GiB, 533 MiB/s) INFO[0061] Migration completed ``` ### Phase 2: Incremental Sync Re-run the `migrate` command to copy only changed blocks. This phase can be repeated multiple times to reduce final cutover time. ### Phase 3: Final Cutover ```bash openstack network list openstack subnet list docker run -it --rm --privileged \ --network host \ -v /usr/lib64/vmware-vix-disklib/:/usr/lib64/vmware-vix-disklib:ro \ --env-file <(env | grep OS_) \ ghcr.io/vexxhost/migratekit:main \ cutover \ --vmware-endpoint \ --vmware-username root \ --vmware-password "" \ --vmware-path /ha-datacenter/vm/ \ --flavor \ --network-mapping mac=,network-id=,subnet-id= \ --debug ``` Cutover sequence: 1. Create Neutron port 2. Perform final incremental sync 3. Power off source VM 4. Create volume and Nova instance 5. Boot the migrated VM --- ## Verification ```bash openstack volume list openstack server list openstack console url show ssh ubuntu@ ``` --- ## Troubleshooting | Issue | Cause | Resolution | | --- | --- | --- | | Authentication error | Domain variables misconfigured | Remove `OS_PROJECT_DOMAIN_ID` and `OS_USER_DOMAIN_ID` | | CBT not enabled | Missing CBT flags | Verify `.vmx` configuration | | Network mapping failed | MAC mismatch | Validate VMware and Neutron mappings | | Kernel panic on boot | Unsupported virtual hardware version | Use older `virtualHW.version` | --- ## Performance Observations | Metric | Result | | --- | --- | | Disk size | 25 GB | | Throughput | ~533 MiB/s | | Full sync time | ~47 seconds | | Downtime | 5–10 minutes | | Data loss | None | --- ## Operational Best Practices **Before migration** * Test with non-production workloads * Enable CBT early * Maintain backups * Perform multiple sync cycles **During migration** * Monitor network throughput * Keep source VM running until cutover * Review logs in debug mode **After migration** * Validate application behavior * Update DNS and routing * Monitor system performance * Retain source VM temporarily for rollback --- ## Conclusion MigrateKit provides a **clean and reliable migration path** from VMware ESXi to OpenStack when Change Block Tracking is available. Key strengths: * Minimal downtime * Deterministic workflow * Open-source and production-ready Limitations: * Requires CBT support * Dependent on ESXi API access * Network performance impacts total time --- ## References * MigrateKit GitHub * VEXXHOST: Introducing MigrateKit * VMware VDDK Documentation * OpenStack Official Documentation