Once you have adopted your strategy and chosen your vendor, you'll want to plan out your migration and create a road map. The more carefully you gather data and plan your migration, the better your chances for a smooth and successful cloud migration.
Here are factors, considerations, and steps to help you create your cloud migration road map.
According to Gartner, these are the five ways you can move applications into the cloud:
Rehost for infrastructure as a service (Iaas)
Change application's infrastructure configuration and redeploy applications to a different hardware environment. While it is possible to migrate applications faster when you don't change their infrastructure configurations, you will miss out on the scalability benefit of IaaS.
Refactor for platform as a service (PaaS)
Applications are run on a cloud provider's infrastructure. PaaS is backward compatible, which allows developers to leverage code and preserve your organization's investment in it. The drawback is that refactoring can be a significant development project that requires time and upfront costs.
Revise for PaaS or IaaS
Extend or modify existing code base to accommodate legacy modernization needs. Use refactor or rehost options for cloud deployment. Organizations can use the revise method to leverage the provider's infrastructure and cloud characteristics. Like the refactor option above, the revise method can be a time- and cost-intensive option.
Rebuild on PaaS
Recreate the solution for PaaS and discard existing application code. The rebuild method offers many benefits, including access to innovative features and tools from the provider's platform. The main disadvantage is vendor lock-in. If the provider ever makes a change that you cannot accept, you might be forced to switch providers and abandon some or all your assets.
Replace with software as a service (SaaS)
Discard your existing applications and adopt commercial software delivered as a service. This option can save upfront costs and can be deployed fast. The drawbacks include vendor lock-in, inconsistent data semantics, and access issues.
How to Audit Your Resources
Needs: Workloads (current and estimated future), security, compliance, storage, and business continuity.
Capacity: How much data is your organization generating and storing? What are your projected storage needs for the next 12-18 months?
Existing hardware life cycle: Where is your infrastructure in terms of support agreements, warranty, and leases?
Software: Can you leverage your migration to take advantage of service provider licensing models or flexible subscriptions?
Optimization: Can you use the cloud to open new market segments, create new apps or services, or reduce operating costs?
Decide What Will Stay and What Will Move to the Cloud
Depending on several factors, some of your applications and data might stay on premises while the rest is migrated to the cloud. Here are several considerations that could affect what should migrate to the cloud.
Security: Do you need a secure connection, or can you access data over the public internet? Which applications and data need to be held to PCI and HIPPA compliance standards via SAS 70 Type II audit standard?
Performance: Are there applications that require fast access to large data pools? You may want to keep these on premises.
Costs: Direct costs, including hardware and software, licenses, warranties, supplies, and contracts. Operational costs, including labor, maintenance, connectivity, and housing. Administrative costs, including resources needed from other departments, such as finance, procurement, and human resources.
Create a Network Map
Before you begin your cloud migration, you'll want to map all the interdependencies and components of your organization's applications and processes. The map should include:
- Networking infrastructure
- Data flow
The better you understand your current environment and how users interact with it, the better you will be able to plan and execute a smooth migration.
How to Set Your Application Migration Schedule
Choose the easiest and least critical applications and move them to the cloud first. This allows you to find and mitigate any unforeseeable issues while the stakes are low. Select the applications and data that are the most suitable for the cloud and start with those first.