About migration planning

After you complete the discovery and assessment phase, and set up your foundation design, you can start planning your migration by categorizing your workloads into migration waves.

This and the following documents describe how to plan a successful migration and minimize the associated risks.

Before you begin

Before you start your migration planning, complete a workload discovery and assessment, and create an overall migration strategy that consists of the following tasks:

  • Cataloging workloads, such as applications, services, and databases, that you identified for migration.
  • Mapping the workloads to infrastructure components.
  • Mapping of dependencies.
  • Identifying high level migration and modernization paths (rehost, replatform, refactor, re-architect, replace, retire).

Then, use the Cloud Foundation Toolkit to build your foundation on Google Cloud.

The Cloud Foundation Toolkit includes resources to help you get started with the following aspects of your new cloud infrastructure:

  • Identity and Access Management
  • Resource management
  • Networking
  • Data management
  • Infrastructure as code
  • Logging, monitoring, and billing
  • Security foundations
  • GKE foundations

Basic migration concepts

A cloud migration project represents the entire process that your organization follows to migrate the applications to Google Cloud.

Each cloud migration project is divided into waves. A wave is a group of applications that share common characteristics or interdependencies, as identified by the workload discovery and assessment. Standalone applications and databases are typically good candidates for a first migration wave given their low external dependencies. On the other hand, applications with significant interdependencies would constitute a complex migration wave that requires additional planning.

Applications within a migration wave are divided into move groups and migrated to Google Cloud in sprints. A move group is a group of infrastructure resources and workloads that you need to migrate together. These resources and workloads can be part of the same application or a group of applications that are interdependent.

A cloud migration project is divided into waves and move groups

Business capability is one of the most critical aspects to determine the move groups. For example, supply chain management and inventory management in retail, fraud monitoring in banking, claim processing in insurance, represent business capability areas in the respective domains. Considering business capability is critical to ensure minimal or no disruption to business service performance and availability during and after migration.

Within a business capability area, you need to perform the migration according to your different environments. Research and development (R&D) environments are typically the first to be migrated. This helps you identify and mitigate any blockers that might prevent or slow down the migration. You can then follow the best practices and mitigation activities as you progress through the migration of R&D, pre-production and production environments.

Discovery and assessment needs to be an ongoing process, with the data collection getting increasingly refined and more accurate over time. This allows you to constantly improve the accuracy of workload-specific data, which helps identify workload-specific risks associated with the cloud migration.

Typically, the first wave of discovery and assessment provides a high-level of directional dependency mapping of infrastructure components and workloads from an infrastructure perspective. This helps you put together a plan for the first migration wave that is more directional in nature, primarily aimed at improving and optimizing elements of the Google Cloud architecture—for example, VM types, storage classes, landing zone design, high-level capacity sizing based on computational and I/O throughput requirements.

In addition, run a migration risk assessment effort in parallel with discovery and assessment. The aim is to calibrate and detail the workload-specific risks associated with the migration, and initiate appropriate mitigation actions. Some examples of such risks are listed in the following pages.

The following diagram shows the whole migration process at a glance.

Diagram of the migration planning and execution process.

What's next