Making the Move
At a high level, the process of migrating to Oracle Cloud Infrastructure is virtually the same whether an organization is moving a single application or a complex collection of integrated environments. Every cloud migration requires key steps like assessment, planning, target environment provisioning, and cutover. But the details of each step may vary significantly depending on what type of environment is being migrated.
Let's take a close look at the phases of the cloud migration process and the various options for carrying out each step.
The most successful cloud migrations begin with a detailed inventory and assessment of on-premises IT resources. The point of the inventory and assessment is to identify opportunities to optimize the IT environment in preparation for the migration. Thorough assessments help organizations create a cost-efficient and seamless migration plan. The assessment should cover:
Identity all software applications, their versions, and their dependencies. This is essential to proper planning and helps organizations gauge the complexity of the migration. Work with stakeholders to understand how critical each application is to the business and include that information in the assessment. Organizations should inventory each deployment environment, including development, application testing, integration, user acceptance testing, staging, and production environments.
Inventory all database versions and make note of the different data types stored within them. Identify any data types that may fall under the purview of regulatory compliance requirements. Include database performance characteristics such as throughput levels; any database replication in the environment; and backup policies. Identify opportunities to eliminate or consolidate databases.
Include an inventory of all licenses for operating systems (OSes), databases, application software, and appliances. This information helps migration teams ensure they are in compliance with licenses when re-deploying resources in the cloud. Licenses may or may not be portable to the cloud, while some licenses may be portable with certain modifications or upgrades.
Applications and data types may be subject to regulatory compliance directives like HIPAA and FedRAMP. Oracle Cloud Infrastructure has certifications for these and other key compliance mandates. See Oracle's compliance page for more information.
Organizations may have several different types of storage in on-premises IT environments. Make note of each storage type and the amount of data housed within each one. Capture information about access patterns, performance requirements, backup policies, and any data that may be subject to compliance requirements.
The server inventory should include a list of all physical and virtual servers; all virtualization environments and their versions; and all OSes and their versions. Capture the key characteristics of any physical or virtual servers, including cores, memory, local storage, and network interfaces. Make note of performance characteristics like speeds and utilization levels.
List any third-party physical or virtual appliances. Appliances may need to be modified or replaced with options that provide similar or identical functionality in Oracle Cloud Infrastructure.
A detailed assessment of the source environment's network architecture helps migration teams architect an optimal target network in Oracle Cloud Infrastructure. List all subnets; all inbound and outbound security rules; measurements of provisioned and utilized bandwidth; firewalls; private and public IP ranges and addresses; and domain names. Oracle Cloud Infrastructure may not allow for the same IP ranges. Security rules may require modification as well.
Using the assessment as a guide, the next step is to create a detailed multi-phase cloud migration plan, with each phase focusing on the migration of specific subsets of related resources. This is also a good time to consider upgrading resources like databases and business applications, and purchasing any add-ons required for license portability to the cloud. Organizations typically break the migration process into phases based on one or more of following criteria:
Many customers begin by migrating low-complexity applications that have minimal or no dependencies. Then they move on to high-complexity applications that may be running on legacy OSes, mainframes, or that may have related components that need re-licensing.
Another strategy is to migrate non-critical applications first and then move on to more important business-critical applications.
Deployment Environment Type
Some organizations choose to migrate all deployment environments at the same time. Others migrate them one at a time based on risk considerations. For example, low-risk environments like development and testing typically go first, followed by user acceptance training, integration, and finally, high-risk production environments.
One low-risk migration strategy involves creating a complete disaster recovery environment in Oracle Cloud Infrastructure. Organizations then switch to using the Oracle Cloud Infrastructure backup deployment as the production environment, and the on-premises environment for disaster recovery.
As part of the planning process, migration teams need to map on-premises IT resources to the right Oracle Cloud Infrastructure resources. This helps teams model the costs of the Oracle Cloud Infrastructure target environment and identify opportunities to fine-tune the deployment and lower costs.
Be sure to conduct test migrations with low-risk resources. This will help migration teams familiarize themselves with Oracle migration processes and identify any problems with the step-by-step plan for migration. There are many tools available for migrating databases, including Golden Gate Cloud Service, Oracle Recovery Manager (RMAN), and Oracle Data Guard. Visit Oracle's Migration Partners page to learn about available tools and third-party companies that help organizations execute successful migrations.