Migrations

Definition

Migration refers to the process of transferring Virtual Machines and their associated resources from a VMware environment to an OpenStack environment. It involves multiple steps, including planning (creating a Migration Plan), discovery (fetching VM resource information), and the actual migration execution. During migration, users provide details such as migration name, and description, select VMs, map networks, map volume types, and configure specific parameters for each VM. The goal is to seamlessly move VM workloads while preserving their configurations and ensuring compatibility with the target OpenStack environment. Successful migration results in VMs running efficiently within the OpenStack infrastructure.

Creation

Check the prerequisites before initiating the migrations.

Once the VMs of the Migration Plan are discovered ( Discover VMs ), the user can initiate the migration.

Trilio provides 3 types of migrations and the user can choose as per their need, more details can be found here.

1. Dry-run Migration:

   • Create VMs on OpenStack with attached storage volumes, networking, and security groups for testing purposes while migrating the VM snapshot data from VMware.

2. Cold Migration:

   • Shut down VMware virtual machines and then migrate them to OpenStack. This process can take minutes to hours and may cause significant downtime, making it more disruptive.

3. Warm Migration:

   • Leverage VMware snapshots and the Change Block Tracking feature to migrate VMs with minimal disruption. Take snapshots, copy changed blocks, and then repeat the process after shutting down the VMs. The downtime can be significantly lower than that of a Cold Migration.

   • Users can choose between an automatic cutover for a hands-free migration experience or a manual cutover for a more controlled migration process.

While initiating the migration, the user needs to provide a few more below-mentioned information to ensure a seamless migration of the VMs.

Details

To perform the actual migration, users need to:

• Provide a name and description for the migration.

• Choose the type of migration from a drop-down menu.

Network Mapping

During migration, users can:

• Map-enabled networks in Guest VMs to OpenStack Networks.

• Trilio automatically detects networks, providing a seamless mapping experience.

Volume Types Mapping

Users need to:

• Map Datastores detected from the migration plan VMs with OpenStack volume types.

• This ensures proper mapping of storage resources during migration.

VM Selection

Users must:

• Select VMs mapped to the Migration Plan for migration.

• For each VM, choose the correct flavor and Availability Zone.

• Specify configurations for disks to be created on OpenStack.

• For the VMs that are UEFI booted, a glance image must be selected. Refer to this page for more details.

There are certain limitations that have to be taken care of by the user once the migration is successful, please refer to the Limitations page for more information.

Resume Cutover

This option applies only to warm migrations with manual cutover (default).

Once the migration process reaches the stage where the second snapshot of the source VM has been successfully uploaded, the migration enters a Paused state. At this point, the process waits for the user to perform the Resume Cutover action.

Resuming cutover allows Trilio to shut down the source VM and begin the final stage of data transfer.

There is no time limit for this wait; however, it is recommended to resume the operation as soon as possible. Delaying may result in additional data being written to the source VM, which can increase the overall cutover time.

Cancel Migration

At any stage, if users decide not to continue with the migration, they can cancel the operation. This action reverts any changes and cleans up the OpenStack resources created for that migration.

The Cancel option is available for all types of migrations and at any stage, including when the migration is in a Paused state.

Migration Overview

The Migration Overview page provides a comprehensive summary of a migration job. It displays key details, progress indicators, and status information to help users monitor and analyze the migration process.

Details Displayed

• Name – The unique name assigned to the migration job.

• Description – An optional user-provided description for easier identification.

• Migration Type – Indicates the type of migration (e.g., warm, cold).

• Status – Current state of the migration (e.g., Running, Paused, Completed, Failed).

• Warnings – Any warning messages generated during the migration process.

• Total Size – The total amount of data included in the migration.

• Total Time Taken – The overall time consumed for the migration to complete.

Progress Tracking

• Progress Messages – A detailed list of migration tasks, each showing:

  • Task name

  • Progress percentage

  • Status (e.g., In Progress, Completed, Failed)

  • Time taken per task

• Overall Progress Percentage – An aggregated percentage representing the overall completion status of the migration.

Execution Environment

• Workload Manager Host – The hostname of the workload manager where the migration is scheduled.

• Migration Options – The options selected while invoking the migration (e.g., automatic or manual cutover, additional configuration settings).

Migration Deletion

Deletion of the initiated Migrations can be done to clean up the unnecessary entries in the list. Please note that deleting a migration does not clean up the migrated VMs or their associated resources from OpenStack. The user will have to explicitly remove the migrated resources if necessary.

How-to Guide: Initiating a Migration