Workload Migration Steps for OpenStack

Migrating workloads to OpenStack can give you more control, lower costs, and greater flexibility. But like most things in cloud technology, it requires careful planning to avoid common challenges like service compatibility, network issues, and resource management.

Quick Steps for Migration:

1. Plan Ahead: Inventory your workloads, figure out resource needs, and note all dependencies.
2. Set Priorities: Start with less important applications before moving to mission-critical systems.
3. Prepare OpenStack: Configure networking, storage, and quotas to match workload requirements.
4. Migrate Data: Use tools like a Universal Conversion Host to transfer volumes and ensure data integrity.
5. Launch Instances: Create VMs, attach volumes, and verify network connectivity.
6. Test Thoroughly: Check applications, networks, and data accuracy post-migration.

Let’s get into the details!

Understanding OpenStack Workload Migration Types: Cold, Live, and Warm

Before we get into the steps, it’s important to figure out which migration type you’ll use for each of your workloads. Migrating workloads to OpenStack involves moving your virtual machines (VMs) and their associated data from your current infrastructure to the OpenStack cloud environment. The best approach depends on your workload’s requirements and tolerance for downtime. OpenStack is capable of supporting cold migrations, live migrations, and warm migrations.

Here’s more information about each type:

Cold Migration

Cold migration, sometimes referred to as offline migration, is the simplest and most universally compatible migration method. It involves the following steps:

1. Shutdown the VM: The virtual machine in your source environment is completely shut down. This results in downtime for the services running on that VM.
2. Export the VM Image: The VM’s disk image (and configuration) is exported from the source hypervisor in a compatible format (e.g., QCOW2, OVA, VMDK, depending on your source and OpenStack image import capabilities). For example, in VMware vSphere, you can export a VM to OVF/OVA format.
3. Import the VM Image to OpenStack Glance: The exported VM image is uploaded to OpenStack Glance, the image service. Glance stores and manages VM images that can be used to create instances.
4. Create an Instance from the Image: In OpenStack Nova (compute service), you create a new instance based on the imported Glance image. Nova provisions and manages compute resources in OpenStack.
5. Configure Networking and Storage: Attach networks, assign floating IPs (if needed), and configure any necessary persistent storage volumes within OpenStack. OpenStack Neutron handles networking, and Cinder provides block storage volumes.
6. Power On the Instance: Start the newly created instance in OpenStack.

Suitable for:

• Non-Critical Workloads: Applications that can tolerate scheduled downtime without significant business impact, such as development servers or staging environments.
• Simple Migrations: When minimal complexity is desired, and downtime is acceptable.
• Initial Migrations to OpenStack: Often a good starting point to familiarize yourself with the platform and the basic migration workflow.
• Workloads With Licensing Restrictions: Easier to manage with planned downtime.

Considerations:

• Downtime: Significant downtime is incurred during the migration process, lasting from the shutdown of the source VM until the new instance is operational in OpenStack. This downtime duration depends on the size of the VM image, network bandwidth, and OpenStack environment responsiveness.
• Simplicity: Relatively straightforward to execute and troubleshoot. The process is well-defined and less prone to complex errors compared to live migration.
• Compatibility: Generally compatible with a wider range of source virtualization platforms and hypervisors as it relies on standard image export/import mechanisms.

Example Scenario: Migrating a development server, a batch processing application, a testing environment, or any service that can tolerate a planned maintenance window without significant business disruption.

Live Migration

Live migration offers the significant advantage of minimal to zero downtime for your services during the migration process. It allows you to move a running VM from your source infrastructure to OpenStack without interrupting its operation. This is achieved by transferring the VM’s memory, storage, and network state while it’s still running.

Prerequisites for Live Migration to OpenStack

• Shared Storage (Highly Recommended): Live migration typically relies on shared storage accessible by both your source environment and the OpenStack compute nodes. This could be shared block storage (e.g., iSCSI, Fibre Channel) or distributed file systems (e.g., Ceph, GlusterFS). Shared storage simplifies live migration by allowing both the source and target hypervisors to access the VM’s disk simultaneously. While technically possible without shared storage in some advanced configurations (using block migration), shared storage greatly simplifies and improves the reliability of live migration in OpenStack.
• Network Connectivity: Robust and low-latency network connectivity between your source infrastructure and the OpenStack environment is crucial for efficient data transfer during live migration. A dedicated migration network is often recommended to isolate migration traffic and ensure sufficient bandwidth.
• Compatible Hypervisors: Ensure the hypervisors in both your source environment and OpenStack are compatible with live migration and support the same virtualization technologies. For example, migrating from KVM to KVM within OpenStack is commonly supported. Migrating between different hypervisor technologies might be more complex or not directly supported by standard OpenStack tools and may require specialized solutions.
• OpenStack Configuration: Live migration needs to be properly configured within your OpenStack Compute (Nova) service. This might involve settings related to migration networks, resource allocation policies, and potentially enabling live migration features in the hypervisor configuration.

General Steps for Live Migration (Conceptual – Specific steps will vary based on your source environment and OpenStack setup)

1. Initiate Live Migration from Source or OpenStack: The live migration process can often be initiated from either your source virtualization management platform (if it has integration capabilities) or directly through OpenStack commands (using the OpenStack CLI or Horizon UI, if supported for live migration from external sources).
2. Pre-Copy Phase: OpenStack (or the migration tool) begins copying the VM’s memory and disk state to the target OpenStack compute node while the VM is still running in the source environment. This initial copy happens in the background, minimizing service interruption.
3. Cutover Phase (Brief Downtime Window, Ideally Minimal): Once most of the data is pre-copied, there’s a short cutover phase. The source VM is briefly paused, the remaining memory changes are synchronized, and the VM is resumed and starts running on the OpenStack compute node. This cutover is designed to be very quick, ideally in milliseconds, resulting in near-zero downtime for the application.
4. Post-Migration Verification: After the migration, verify the VM is running correctly within OpenStack, that all services are functioning as expected, and that network connectivity is maintained.

Suitable for:

• Business-Critical Workloads: Applications that require continuous availability and cannot tolerate significant downtime, such as e-commerce platforms, production databases, or customer-facing web applications.
• Services With Strict SLAs: Environments where service level agreements demand minimal interruption and high uptime.
• Large and Complex VMs: Live migration can be beneficial for large VMs where cold migration downtime would be excessively long and disruptive.
• Compliance Requirements that mandate minimal service interruption.

Considerations:

• Complexity: Live migration is more complex to set up and execute than cold migration, requiring careful planning and configuration of shared storage, networking, and hypervisor compatibility. Troubleshooting live migration issues can also be more challenging.
• Prerequisites: Shared storage and proper network setup are essential and must be carefully planned and implemented. Lack of shared storage or insufficient network bandwidth can lead to migration failures or prolonged cutover times.
• Performance Overhead (During Migration): There can be some performance overhead on both the source and target VMs during the pre-copy phase of live migration as resources are used for data transfer. This overhead should be monitored and planned for to minimize impact on application performance.
• Potential for Issues: While designed for minimal downtime, live migrations can sometimes encounter issues (network glitches, storage problems, hypervisor incompatibilities) that might require troubleshooting and potentially a fallback plan.
• Hypervisor Compatibility: Live migration capabilities and support levels can vary depending on the hypervisor technologies used in both the source and OpenStack environments.

Example Scenario: Migrating a production database server, a critical web application, an e-commerce platform, a VoIP system, or any application that needs to remain online and accessible with minimal to no interruption throughout the migration process.

Warm Migration (Staged/Hybrid Approach)

Warm migration represents a middle ground between cold and live migration. It aims to reduce downtime compared to cold migration but might be less complex than full live migration, particularly when shared storage for live migration is not readily available or feasible. It’s often a staged approach that combines initial data synchronization with a brief planned downtime window.

General Steps for Warm Migration (Conceptual)

1. Initial Data Synchronization (While VM is Running): You begin replicating the VM’s data (disk contents) from the source environment to OpenStack while the VM is still running. This can be done using tools like rsync, block-level replication software (e.g., dd with netcat), or other data synchronization mechanisms. This pre-sync step significantly reduces the amount of data that needs to be transferred during the final cutover window.
2. Planned Downtime Window: Schedule a short downtime window for the final cutover. The duration should be estimated based on the data change rate since the initial synchronization and the time needed for the final delta synchronization.
3. Shutdown VM (Source): During the planned downtime window, gracefully shut down the VM in the source environment. This ensures data consistency before the final synchronization.
4. Final Data Synchronization (Delta Sync): Perform a final, quick synchronization to capture any changes that occurred since the initial sync and while the VM was running up until shutdown. This is often a much smaller amount of data compared to the initial full sync.
5. Import/Create in OpenStack: Import the synchronized data into OpenStack as a new instance. Depending on the synchronization method, this may involve creating a new Glance image from the synchronized data or directly creating a Nova instance from the synchronized storage.
6. Power On Instance (OpenStack): Start the instance in OpenStack.

Suitable for:

• Workloads with moderate downtime tolerance: Applications that can endure a brief, planned downtime window (e.g., minutes to a short period of hours) but where prolonged cold migration downtime is undesirable. This might include internal applications, less critical databases, or services that can be taken offline during off-peak hours.
• Large datasets without shared storage readiness for live migration: Warm migration can be a viable option when setting up shared storage for live migration is too complex, costly, or not immediately feasible. It allows for migrating large VMs without the extensive downtime of cold migration.
• Complex applications needing more control over cutover: Allows for a more controlled and planned cutover process compared to fully automated live migration, giving more flexibility for coordinating application-level cutover steps.

Considerations:

• Reduced Downtime (Compared to Cold): Downtime is significantly less than cold migration, potentially reduced to a short maintenance window, but more than live migration (which aims for near-zero).
• Complexity (Moderate): More complex than cold migration but potentially less complex than full live migration setup. Requires setting up and managing data synchronization tools, scripting the staged process, and careful planning of the downtime window.
• Data Consistency: Maintaining data consistency is crucial, especially during the initial and final synchronization phases. Ensure proper shutdown procedures and synchronization methods are used to prevent data corruption or loss.
• Downtime Estimation: Accurately estimating the final downtime window is important for planning and communication. This requires understanding the data change rate and synchronization performance.
• Tooling and Scripting: Warm migration often relies on scripting and command-line tools for data synchronization and instance creation. Familiarity with these tools is necessary.

Example Scenario: Migrating a file server, a content management system (CMS), an application server, a large but less critical database, or any application with a large dataset where a planned, short maintenance window is acceptable, but prolonged cold migration downtime is not. This could also be suitable when transitioning away from infrastructure where setting up shared storage for live migration is impractical.

Planning Your Migration

Your first step is to create a detailed plan. A well-thought-out plan can keep potential disruptions at bay and helps your workload migration go smoothly. As you’re creating it, keep in mind the different migration types above and match each type with the workload you’ll use it with. You don’t want any confusion coming into play during the migration and suddenly an important instance is shut down when it’s supposed to stay live!

We also highly recommend setting up a test OpenStack environment to practice the migration process and validate configurations in a non-production environment before migrating production workloads. This can be notated in your plan.

Analyzing Current Workloads

Start by taking a complete inventory of your infrastructure. OpenStack’s built-in tools like Nova, Cinder, and Neutron can provide insights into workload requirements. You’ll want to pay attention to these main areas:

Workload Assessment Checklist

Inventory VMs

• Create a detailed list of all virtual machines to be migrated.
• Document their specifications: CPU, RAM, Storage (size and type), Network configuration (interfaces, IP addresses, VLANs).
• Record the operating system, applications running, and any critical configurations.

Dependency Mapping

• Identify all dependencies between VMs and external services. This includes databases, application servers, APIs, shared file systems, load balancers, DNS, etc.
• Document the network communication paths and ports required for these dependencies.

Application Requirements

• Understand the performance requirements of each application: CPU, memory, storage I/O, network bandwidth.
• Define uptime SLAs (Service Level Agreements) for each application and service.
• Determine data sensitivity and security requirements (encryption, access control, compliance).
• Identify any specific application configurations or settings that need to be preserved during migration.

Resource Needs in OpenStack

• Based on the workload assessment, estimate the required compute, storage, and network resources in your OpenStack environment to accommodate the migrated workloads.
• Consider future scalability needs and growth projections.

Testing and Rollback Plan

• Develop a detailed testing plan to validate the functionality, performance, and stability of migrated workloads in OpenStack. This plan should include functional testing, performance testing, and application-specific tests.
• Create a comprehensive rollback strategy in case of migration failures or unexpected issues. This should include steps to quickly revert back to the source environment if necessary. Consider backup and snapshot strategies as part of the rollback plan.

Timeline and Schedule

• Create a realistic timeline for the migration project, including phases for planning, preparation, execution, testing, and post-migration optimization.
• Schedule migration windows, especially for workloads requiring downtime, considering business impact and off-peak hours.

Choose Your Migration Type

• Assess Workload Downtime Tolerance: How much downtime can your application or service tolerate? Zero, minimal, moderate, or significant? This is the primary factor in choosing between live, warm, and cold migration.
• Evaluate Infrastructure Capabilities: Do you have shared storage available and configured between your source environment and OpenStack? Is your network infrastructure robust and low-latency? Are your hypervisors compatible for live migration? The answers to these questions will influence your options.
• Consider Complexity and Resources: Live migration is more complex to set up and manage. Do you have the technical expertise and resources to handle this complexity? Warm migration is a middle ground in terms of complexity. Cold migration is the simplest.
• Licensing and Application Dependencies: Consider application licensing implications of downtime. Also, map out application dependencies – are there other VMs or services that rely on the VM you are migrating? How will their dependencies be handled during and after migration?

Setting Migration Order

Start with less important or complicated applications that have fewer dependencies. This allows you to gain experience and ensure things are happening how they should be before moving more complex workloads.

Setting Up OpenStack

Prep your OpenStack environment to handle the migration process:

Project/Tenant Creation

• Create a dedicated OpenStack project (tenant) to host the migrated workloads. This helps with resource isolation, access control, and organization. Use the Horizon UI (“Identity” -> “Projects” -> “Create Project”) or the OpenStack CLI (openstack project create).
• Define appropriate quotas for the project based on your resource needs (compute, storage, network).

Network Setup (Neutron)

• Configure networks in OpenStack Neutron to match or improve upon the network connectivity of your source environment.
• Create internal networks for VM-to-VM communication within OpenStack.
• Create external networks to provide internet access or connectivity to external resources.
• Consider using VLANs for network segmentation and isolation if needed.
• Configure security groups to control inbound and outbound traffic to your instances, enhancing security.

Storage Configuration (Cinder and Swift)

• Set up block storage volumes using OpenStack Cinder to provide persistent storage for your instances. Define volume types based on performance requirements (e.g., SSD-backed for high I/O workloads).
• If needed, configure object storage using OpenStack Swift for storing backups, images, or other unstructured data.

Image Availability (Glance)

• Ensure that base OS images required for your migrated workloads are available in OpenStack Glance. OpenStack often provides a catalog of readily available images.
• If you need to use custom OS images, prepare them and upload them to Glance (using the OpenStack CLI: openstack image create, or Horizon UI).

Flavor Selection

• Define or select appropriate flavors (instance sizes) in OpenStack Nova that match the resource requirements of your VMs. Flavors define the amount of CPU, RAM, and disk space allocated to an instance.
• Review existing flavors and create custom flavors if necessary to precisely match your workload requirements.

Security Considerations

• Review and configure security groups to restrict network access to your instances based on the principle of least privilege.
• Manage SSH key pairs for secure instance access. Generate key pairs in OpenStack (“Project” -> “Compute” -> “Key Pairs” in Horizon, or openstack keypair create via CLI).
• Implement other security best practices relevant to your OpenStack environment and workloads (e.g., OS hardening, intrusion detection).

Source Environment Preparation (as needed for specific migration types)

For Live Migration

• Shared Storage Setup and Verification: Ensure shared storage is correctly configured and accessible by both your source hypervisors and the OpenStack compute nodes that will host the migrated VMs. Verify storage connectivity and permissions. Test writing and reading data from both environments to the shared storage.
• Network Connectivity Verification: Confirm robust and low-latency network connectivity between your source environment and the OpenStack environment, especially on the designated migration network (if applicable). Test network bandwidth and latency.
• Hypervisor Compatibility Check: Verify compatibility between the hypervisors in your source environment and OpenStack, particularly regarding live migration capabilities and virtualization technology support. Review hypervisor documentation and OpenStack compatibility guides.

For Warm Migration

• Data Synchronization Tool Setup: Install and configure your chosen data synchronization tool (e.g., rsync, block replication software) in both the source and target environments. Test connectivity and data transfer.
• Access Permissions: Ensure the synchronization tool has the necessary access permissions to read data from the source VMs and write data to the prepared storage in OpenStack. Consider security implications and use secure transfer methods if necessary.

For a quicker setup, consider hosted solutions. OpenMetal, for example, offers private clouds that are ready to deploy in less than 45 seconds. This allows teams to focus on the migration itself rather than spending time on infrastructure setup.

Migration Steps

The steps will vary quite a bit depending on the migration type you have chosen. Follow the steps relevant to your selected method.

Cold Migration Execution Steps

1. Shutdown the VM in your source environment. Use the appropriate shutdown procedure for your source virtualization platform (e.g., gracefully shutdown the guest OS from within the VM, or use the hypervisor management console to power off the VM). Ensure the VM is completely powered off before proceeding. Refer to your source hypervisor documentation for specific shutdown instructions (e.g., VMware vSphere, Hyper-V, KVM, etc.).
2. Export the VM Image. Export the VM’s disk image from your source hypervisor to a compatible format (e.g., OVA, QCOW2, VMDK). For example, in VMware vSphere, you can export a VM to OVF/OVA format by right-clicking the VM and selecting “Export” -> “Export OVF Template.” Choose a location to save the exported image file.
3. Access your OpenStack environment. Log in to your OpenStack environment using the Horizon Web UI or the OpenStack Command Line Interface (CLI). Ensure you are working within the correct project/tenant you created for migration.
4. Upload the VM Image to Glance.
   • Using the OpenStack CLI:
     openstack image create "<image_name>" --disk-format qcow2 --container-format bare --file <path_to_your_exported_image.qcow2>Replace <image_name> with a descriptive name for your image (e.g., “migrated-webserver-image”) and <path_to_your_exported_image.qcow2> with the actual path to your exported image file (e.g., /tmp/exported-vm.qcow2). Ensure the --disk-format and --container-format options are correct for your image format. You can use openstack image create --help for more options.
   • Using Horizon UI:
     • Navigate to “Project” -> “Compute” -> “Images” in the Horizon dashboard.
     • Click the “Create Image” button.
     • Fill in the image details:
       • Name: Enter a name for the image (e.g., “migrated-webserver-image”).
       • Description (optional): Add a description.
       • Image Source: Choose “Image File”.
       • Image File: Browse and select your exported VM image file.
       • Format: Select the correct disk format (e.g., QCOW2, OVA, VMDK) and container format (usually “bare”).
       • Public/Protected/Shared: Set image visibility as needed (usually “Project” for project-private, “Public” for wider access within the OpenStack cloud).
     • Click “Create Image”. Wait for the image upload to complete and the image status to become “Active”.
5. Create an Instance from the Imported Image.
   • Using the OpenStack CLI:
     openstack server create --flavor <flavor_name> --image "<image_name>" --network <network_id> "<instance_name>"Replace <flavor_name> with the desired flavor for your instance (e.g., m1.medium, my-custom-flavor). Use openstack flavor list to see available flavors. Replace <image_name> with the name of the image you uploaded to Glance (e.g., "migrated-webserver-image"). Replace <network_id> with the ID or name of the network you want to connect the instance to (e.g., "private-network", or its UUID). Use openstack network list to see available networks. Replace <instance_name> with a name for your new instance (e.g., "migrated-webserver-01").
   • Using Horizon UI:
     • Navigate to “Project” -> “Compute” -> “Instances” in the Horizon dashboard.
     • Click “Launch Instance”.
     • Details Tab: Enter an Instance Name.
     • Source Tab: Select “Image” as the boot source. Choose the image you uploaded to Glance from the available images.
     • Flavor Tab: Select the desired flavor for your instance.
     • Networks Tab: Select the network you want to connect the instance to.
     • Security Groups Tab: Select appropriate security groups.
     • Key Pair Tab: Select or create a key pair for SSH access.
     • Click “Launch Instance”.
6. Configure Networking and Storage (Post-Instance Creation).
   • Assign a Floating IP (if needed): To make the instance accessible from outside the OpenStack private network, assign a floating IP. In Horizon, go to “Project” -> “Compute” -> “Instances”, click the Actions dropdown for your instance, and select “Associate Floating IP”. Allocate a floating IP if needed or select an existing one and associate it. Using the CLI: openstack floating ip create <external_network_id> && openstack server add floating ip <instance_name> <floating_ip_address>.
   • Create and Attach Volumes (if needed): If your workload requires persistent block storage, create Cinder volumes and attach them to your instance. In Horizon, go to “Project” -> “Compute” -> “Volumes” -> “Create Volume”. After creation, select “Manage Attachments” for the volume and attach it to your instance. Using the CLI: openstack volume create --size <size_gb> --type <volume_type> <volume_name> and openstack server add volume <instance_name> <volume_id>.
   • Configure Security Groups: Review and adjust security group rules to allow necessary network traffic to your instance. In Horizon, go to “Project” -> “Network” -> “Security Groups”. Using the CLI: openstack security group rule create.
7. Power on the Instance in OpenStack. If the instance is not already powered on after creation, start it. In Horizon, go to “Project” -> “Compute” -> “Instances” and click “Start Instance” from the Actions dropdown. Using the CLI: openstack server start <instance_name>.
8. Verify the migrated workload.
   • Access the instance using SSH (if configured) or through the Horizon console.
   • Test all applications and services running on the instance to ensure they are functioning correctly.
   • Verify network connectivity and application functionality from both inside and outside the OpenStack environment.

Live Migration Execution Steps (Conceptual Outline – Specific steps will vary greatly based on source environment and OpenStack setup)

1. Initiate Live Migration. The method to initiate live migration depends heavily on your source environment’s virtualization platform and whether you’re using direct OpenStack live migration commands or a migration tool with OpenStack integration.
   • From Source Environment (If Integrated): Some virtualization platforms may offer tools or plugins to directly initiate live migration to OpenStack. Consult your source platform’s documentation for such features.
   • From OpenStack CLI/Horizon (Potentially for KVM-to-KVM within OpenStack or from compatible external KVM): You might be able to use OpenStack Nova CLI commands like openstack server migrate --live <server_id> or Horizon UI options (if available in your OpenStack distribution) to initiate live migration, especially if your source environment is also KVM-based and configured for compatibility. Note: Direct live migration from completely external environments to OpenStack using standard OpenStack tools is less common and often requires specific configurations or plugins.
   • Using Specialized Migration Tools: For migrations from diverse source environments (e.g., VMware vSphere, Hyper-V to OpenStack), you often need specialized migration tools that handle the complexities of cross-hypervisor live migration. These tools might provide their own interfaces and steps.
2. Monitor the Live Migration Progress. Track the migration process in your OpenStack environment (using Horizon or CLI commands like openstack server show <server_id>). Monitor the pre-copy phase, cutover, and overall progress. Look for any error messages or warnings during the migration.
3. Post-Migration Verification. After the migration is reported as successful, perform thorough verification steps as outlined in the “Verification and Testing” section to ensure the migrated VM and its applications are running correctly in OpenStack with minimal to no downtime experienced by end-users.

Warm Migration Execution Steps (Conceptual Outline – Tooling and scripting will be highly specific)

1. Initial Data Synchronization (While VM is Running). Use your chosen data synchronization tool (e.g., rsync, block replication) to begin replicating data from the source VM’s disks to storage within your OpenStack environment. This step should be performed while the VM is still running in the source environment. Example using rsync (conceptual, adapt to your specific needs and security): rsync -avz --progress source_vm:/data/ /openstack_storage/destination/ (This is a highly simplified example. Real-world warm migration requires more robust tooling, scripting, and error handling, especially for block-level synchronization.)
2. Schedule Downtime Window. Plan a short downtime window for the final cutover. Communicate this maintenance window to stakeholders.
3. Shutdown VM (Source). At the start of the downtime window, gracefully shut down the VM in the source environment.
4. Final Data Synchronization (Delta Sync). Immediately after shutdown, perform a final, quick synchronization to capture any data changes that occurred since the initial sync. Using the same rsync example: rsync -avz --progress source_vm:/data/ /openstack_storage/destination/ (This delta sync should be much faster as it only transfers changes).
5. Import/Create Instance in OpenStack. Depending on how you synchronized data, you may need to create a Glance image from the synchronized data or directly create a Nova instance, pointing it to the synchronized storage location. The exact steps here are very tool-dependent.
6. Power on Instance (OpenStack). Start the instance in OpenStack.
7. Verification and Testing. Perform thorough verification and testing as described in the next section.

For those seeking a simpler migration experience, hosted solutions like OpenMetal’s private cloud infrastructure offer pre-configured environments that make the destination setup much easier.

Verification and Testing After Migration

Once your data migration and instance setup are complete, the next step is validating the environment. This involves testing systems to ensure that applications, networks, and data are functioning as expected. Don’t assume migration success just because the VM starts!

Functional Testing

• Basic Instance Functionality: Verify the instance is reachable on the network (ping, network connectivity tests).
• Application Verification: Access and test all applications and services running within the migrated VM. Use application-specific test procedures to ensure core functionalities are working as expected. Check web applications, databases, APIs, file shares, etc.
• Dependency Testing: Verify that dependencies on other services (internal or external) are correctly resolved from within the OpenStack environment. Check connectivity to databases, APIs, DNS, etc.
• Data Integrity Checks (If applicable): If data integrity is critical for your application, implement specific checks to validate that data was migrated completely and without corruption. This might involve comparing checksums, database record counts, or performing application-level data validation.

Performance Testing

• Baseline Performance Comparison: Compare the performance of the migrated workload in OpenStack to its performance in the source environment. Use performance monitoring tools to measure metrics like CPU utilization, memory usage, disk I/O, and network throughput.
• Application Performance Benchmarks: Run application-specific benchmarks or load tests to evaluate application performance in OpenStack. Compare results to pre-migration benchmarks if available.
• Identify Performance Bottlenecks: If performance is not as expected, investigate potential bottlenecks. Check resource allocation (flavor size), storage performance, network latency, and application configuration within OpenStack.

Application-Specific Tests

• Tailor tests to your specific applications and develop tests that are unique to the applications you migrated. This might include user acceptance testing, specific workflow tests, integration tests, security tests, etc.
• Involve Application Owners/Users: Engage application owners or users in the testing process to get their feedback and ensure the migrated application meets their requirements.

Troubleshooting Tips

• Network Connectivity Issues: If the instance is not reachable, check security groups, network configuration, routing, and floating IP associations. Use ping, traceroute, and network troubleshooting tools within OpenStack.
• Image Import Errors: If image import fails, review image format, size limits, Glance logs for error details. Re-export the image if needed and retry the upload.
• Instance Boot Failures: If the instance fails to boot, check the Nova console logs (accessible via Horizon or CLI: openstack console log <instance_name>) for boot errors, OS issues, or configuration problems. Verify the selected flavor and image are compatible.
• Application Functionality Issues: If applications are not working correctly, review application logs, network configurations, resource allocation, and dependencies within the OpenStack environment. Compare configurations to the source environment.
• Performance Degradation: If performance is poor, monitor resource utilization within OpenStack, check for noisy neighbors (other instances impacting performance), review storage and network performance, and consider adjusting instance flavor or storage types.

Monitoring Post-Migration

• Implement Ongoing Monitoring: Set up monitoring for your migrated workloads within OpenStack using OpenStack monitoring tools (e.g., Ceilometer, Telemetry) or external monitoring solutions.
• Monitor Key Metrics: Track CPU utilization, memory usage, disk I/O, network traffic, application performance, and error logs.
• Establish Alerting: Configure alerting based on monitoring metrics to proactively identify and address any performance issues or failures in the migrated environment.

Experts recommend avoiding assumptions about system functionality without thorough testing. Common pitfalls include overlooking network configuration errors, underestimating data transfer times, and failing to verify data integrity. Thorough planning and execution of testing procedures are crucial to ensure successful migration.

For a more automated approach, OpenStack’s Tempest framework can be a valuable tool. It helps test both infrastructure and application components, minimizing the risk of human error.

Post-Migration Optimization and Management

After successful migration and testing, focus on optimizing your workloads within the OpenStack environment and establishing ongoing management practices.

Resource Optimization

• Right-Sizing Instances: Monitor resource utilization of your migrated instances over time. If instances are over-provisioned (e.g., consistently low CPU or memory usage), consider down-sizing them to smaller flavors to optimize resource consumption and reduce costs.
• Flavor Adjustments: Experiment with different flavors to find the best balance between performance and resource utilization for your workloads. OpenStack makes it easy to resize instances (though resizing may involve a brief reboot in some cases).
• Autoscaling (If Applicable): For applications with fluctuating demand, consider implementing autoscaling within OpenStack. Nova and Heat (Orchestration service) can be used to automatically scale instance resources up or down based on metrics like CPU utilization or request queue length.

Security Hardening in OpenStack

• Regular Security Audits: Conduct regular security audits of your OpenStack environment and migrated workloads.
• Security Group Review and Updates: Continuously review and update security group rules to ensure they are still appropriate and follow the principle of least privilege. Remove any unnecessary open ports or permissive rules.
• Patch Management: Implement a robust patch management process for the operating systems and applications running within your OpenStack instances. Utilize OpenStack image management to create patched base images for new deployments.
• Intrusion Detection/Prevention (If Needed): Consider deploying intrusion detection or prevention systems (IDS/IPS) within your OpenStack environment or within individual instances for enhanced security monitoring and threat mitigation.

Backup and Disaster Recovery

• Backup Strategy: Develop and implement a backup strategy for your migrated workloads in OpenStack. Utilize OpenStack volume snapshots, image backups, or third-party backup solutions. Consider backup frequency, retention policies, and recovery procedures.
• Disaster Recovery Planning: Plan for disaster recovery scenarios. Consider replicating workloads to a separate OpenStack region or availability zone for redundancy. Test your disaster recovery plan regularly.

Ongoing Management

• Instance Lifecycle Management: Establish processes for managing the lifecycle of your OpenStack instances, including provisioning, starting, stopping, resizing, rebuilding, and decommissioning instances.
• Monitoring and Alerting (Continuous): Maintain ongoing monitoring and alerting for your workloads to ensure proactive identification and resolution of issues.
• Documentation: Document your migration process, OpenStack configurations, troubleshooting steps, and ongoing management procedures. Keep documentation up-to-date.
• Stay Informed About OpenStack Updates: Keep abreast of OpenStack updates, security advisories, and best practices. Regularly review and update your OpenStack environment and migration procedures as needed.

Migration Service Options

There are a number of service providers we work with and recommend that can help you migrate from other platforms. Here are just a few!

Popular Open Source Migration Tools and Service Providers

• Coriolis by Cloudbase Solutions
• Acura by Hystax
• virt-v2v and os-migrate by Red Hat
• MigrateKit by VEXXHOST
• FishOS Move It by Sardina Systems

More Migration Service Providers

• Canonical
• Storware
• Trilio
• Mirantis
• Rackspace

Many people are moving from VMware to OpenStack after their acquisition by Broadcom. If that’s the case, check out our webinar with the OpenInfra Foundation and read through their migration guide for some assistance.

You can also apply to get access to a PoC OpenStack cloud with us to test out OpenStack before you make a decision.

Wrapping Up: Migrating Workloads to OpenStack

Careful planning and execution are essential for successful OpenStack migrations. Below, you’ll find a quick overview of key actions and strategies to ensure a smooth migration process and long-term benefits from OpenStack’s capabilities.

Migration Best Practices

Start by setting up core OpenStack services such as glance, cinder, nova, keystone, and neutron.

OpenStack Long-Term Use

OpenStack’s design supports reliable and scalable cloud operations. Tools like Heat streamline resource management and make scaling up or down more efficient.

Some key advantages include:

• Better Resource Use: Features like preemptible instances help you get the most out of your resources.
• Scalability: Its modular setup allows for easy updates and expansions.
• Automation: With OpenStack Heat, you can use templates to manage storage, networking, and applications effortlessly.

If you’d like some assistance, OpenMetal can help by delivering pre-configured, scalable infrastructure solutions tailored to OpenStack environments. Get started below!