However, the process to move a workload from an on-premises data center to a cloud provider is neither simple nor fully automated. It requires careful planning, ample preparation, clear processes and well-considered contingencies. Let's outline the major steps involved in any successful cloud migration.
While migration drivers and goals can vary, the migration process can generally be divided into 12 distinct steps that form the basis of a comprehensive migration checklist.
Why does the business need to migrate this particular workload? There is no one size, purpose or benefit to fit every cloud use case. Migrating a workload to the cloud can improve flexibility, while employing the cloud as a storage target can provide convenience and improve governance. Understand the driving factors, such as cost savings, lower infrastructure burden, scalability, availability and enhancing user satisfaction.
Perhaps the most impactful decision in any cloud migration is whether -- or how much -- to adjust an app to best take advantage of cloud benefits. Depending on their cloud and workload expertise, businesses can employ these four main migration approaches:
Migration alternatives are not all-or-nothing efforts, and different approaches can be adopted for different workloads or use cases. But everything else, from costs to cloud architecture decisions, hinges on which approach you choose.
Have a clear picture of the workload's current cost and performance characteristics. Evaluate the procurement, operational and maintenance costs of the local services required to run it. Carefully assess the workload's local performance, gathering metrics such as transactions per second and bandwidth usage through an application performance monitoring tool. IT and business leaders must objectively compare these costs and performance metrics with what they might be when the workload migrates to cloud infrastructure. Remember, cloud costs become a recurring budget item and require planning. Adding more cloud resources, such as a larger VM instance, can potentially improve workload performance in the cloud, but then cloud costs increase as well.
Next, consider the target environment that best reflects long-term business needs. Typically, the options are private cloud, public cloud and hybrid cloud.
In addition, businesses that have become adept at using one cloud provider can migrate services between two or more cloud providers in what's known as a multi-cloud environment.
There are three primary models for accessing services from a cloud, each with its own level of convenience and user control:
The three principal public cloud providers -- AWS, Google Cloud and Microsoft Azure -- all provide a global presence for IaaS and some PaaS deployments. However, many facets of their clouds' operation can differ significantly, from individual services and APIs to costs and monitoring. Businesses typically choose a provider based on the scope of services offered and specific functionality needed for a given workload. For example, AWS offers a wide array of prepackaged computing instances, while Google Cloud is noted for its machine learning and AI services.
Common options for private cloud include VMware, Dell EMC, IBM Red Hat, Nutanix, Cisco CloudCenter, Oracle Cloud at Customer, Rackspace Private Cloud and HPE, as well as the OpenStack open source platform. Key factors to consider include familiarity with the technology, ease of integration with existing systems and reliability.
IaaS users rely on an experienced cloud architect to design a cloud architecture that is best suited to host the workload. The design typically cobbles together virtualized compute, storage and networking instances, along with an assortment of services such as databases, logging and monitoring tools, event-driven computing and more.
The architecture can be simple and straightforward, such as a single compute and storage instance to manage a simple rehosting. The architecture can also be a complex and intricate environment, supporting distributed, highly reliable workloads for mission-critical production environments or numerous interrelated components that host microservices workloads in the cloud. An architect will also consider the corresponding cloud costs associated with the desired architecture and ensure that the workload's owner budgets properly.
Prudent design also involves significant testing to validate the architecture and ensure that the workload will function properly once deployed and cut over for production. It can involve a proof-of-principle project with a number of iterations and refinements before the actual migration takes place.
Be especially careful to prioritize secondary migration components. Most modern enterprise workloads involve dependencies, such as the availability of a database or an application monitoring tool. Cloud architects must consider the entire scope of a deployment and install and validate any required dependencies before the migration is performed.
With the infrastructure and dependencies in place, IT and business leaders can develop the migration plan, which details the steps needed to conduct the migration from start to finish. A migration plan can be extensive and involve many actions, including the following:
Ultimately, the business implements the migration plan and migrates the workload, dependencies and related data to the prepared cloud infrastructure. The process also involves making network changes, such as configuring domain and IP environments and setting up the security environment so that traffic is successfully and securely redirected to the cloud workload.
To ensure a smooth migration event, test and validate the migration process through careful planning and proof-of-principle projects well in advance. At the same time, keep current, direct contact information for local IT staff and cloud provider technical support in the event of unexpected problems.
Once the migration is completed, thoroughly test the workload for both functionality and performance. Collect and evaluate workload metrics and look for vulnerabilities to mitigate. Start with basic testing by the migration staff, and then open the migrated workload to a series of ever-broader user groups until all users can successfully employ the migrated workload.
After the migration testing and cutover, you'll need to perform ongoing maintenance as with any deployed workload. This includes monitoring, support, troubleshooting, adjustments, refinements and other general upkeep over time. Tasks include the following:
While cloud providers take great pains to simplify and streamline the migration to cloud infrastructures, cloud environments are simply different than traditional data centers. Even the simplest rehosting projects are rarely a direct one-to-one exchange without some translation from local to cloud environments. Any cloud migration project requires clear knowledge of the specific cloud provider's resources, services, cost structure and processes. No migration wizard app can replace basic expertise and experience. This is accomplished in two ways.
First, establish and foster careful communication and collaboration between IT and workload owners. IT and business leaders must agree about the goals and intended benefits of a cloud migration. Technology staff must understand the stakeholders' requirements and expectations in order to create suitable cloud infrastructures. Similarly, business leaders must trust technology staff to set realistic expectations, explain the pragmatic limitations of a migration and ensure that the chosen technology aligns with business needs and goals.
Second, technology staff must know the specific cloud provider's services and APIs and how to use them effectively. Take advantage of the training offered by the provider, such as an AWS solutions architect certification. Companies should consider investing in testing and experimentation to build proof-of-principle deployments to validate a cloud architecture before committing to a migration. Some businesses might opt to expand a cloud-capable staff by hiring cloud architects who are already experienced with specific cloud providers.