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Cloud Migration

AWS Migration: Understanding the Process and Solving 5 Key Challenges

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Amazon Web Services (AWS) provides over 100 cloud computing services, many of them founded on its global Infrastructure as a Service (IaaS) offering, Elastic Compute Cloud (EC2), that allow you to set up dynamic, scalable, automated computing environments. Whether you are migrating to AWS to reduce costs, improve resource utilization, or benefit from new infrastructure capabilities that are unavailable on-premise, migration will be a non-trivial effort.

This article presents Amazon’s basic framework for migration—basic migration phases that are relevant for any AWS migration project, and strategies for migrating each of your applications to AWS, from lift-and-shift to refactor/re-architect. It can also help you plan for common challenges that affect almost every migration project. 

In this post, we’ll examine the process of AWS migration, solve 5 key challenges of AWS migration, and show how NetApp Cloud Volumes ONTAP can help migrate large amounts of data effortlessly to the cloud.

In this article, you will learn:

AWS Cloud Migration Phases

Amazon’s cloud migration guide outlines five phases for migration to the AWS cloud.

Phase 1: Migration Preparation and Business Planning

Get a clear picture of your current situation, the architecture of your existing applications, the challenges you are facing and your business goals. Build a business case for your Amazon migration by defining your objectives. Are you migrating to reduce costs, improve scalability, improve reliability? Based on those goals, determine which applications you need to move to the cloud.

Phase 2: Discovery and Planning

Now that you have an idea of your goals, examine your IT portfolio and consider which migration strategies you’ll use for each of your applications (see the next section). Learn about tools AWS provides that can assist with migration, such as Server Migration Service (SMS), Database Migration Service (DMS) and Amazon DirectConnect, and which might be relevant for your use case.

Phase 3 & Phase 4: Designing, Migrating, and Validating Applications

Create a detailed migration plan for each of your applications. Start with a few apps as a Proof of Concept and see how migration strategies and tools actually play out in your environment. Then get buy-in from stakeholders in your organization and move forward with a full migration plan.

Phase 5: Operate

As applications move to the cloud, you start operating them within AWS and turn off the old versions on-premises (unless you opt for a hybrid model). Build on your experience from applications already running in the cloud for additional applications you’ll need to migrate.

Now that we understand the basic process for migrating any app to AWS, let’s review six alternative strategies that define if and how you will migrate each of your applications to the cloud.

6 AWS Migration Strategies

Amazon recommends six ways to move an on-premise application to the cloud. These strategies are summarized in the image below. For each application or workload, you need to carefully consider which cloud migration strategy is the most appropriate.

Source: Amazon Web Services

  1. Rehost (“lift and shift”)

Moving applications as-is from the on-premise environment to the cloud, using tools like Server Migration Service (SMS) or manual procedures. For more information on how rehosting compares to other migration methods, as well as some of the tools that can help you achieve it, see our blog post on lift and shift.

Suitable for: Large legacy migrations, shortage of cloud technology skills.

Pros: Simpler migration process that doesn’t involve changes to the enterprise business processes and faster time to market.

Cons: Less flexibility, inefficient use of cloud resources, difficult to extend or modify applications.


  1. Replatform (“lift, tinker and shift”)

Moving applications almost as-is, but replacing some components to take advantage of AWS services. For example, moving a legacy application but replacing the self-hosted database with Amazon Relational Database Service (RDS).

Suitable for: Conservative migrations requiring stability but willing to experiment to get more benefits from the cloud.

Pros: Relatively fast migration, requires minimal integration and testing work.

Cons: Limited ability to leverage the benefits of the cloud.


  1. Repurchase (“drop and shop”)

Involves replacing the application entirely with Amazon or cloud services. For example, discontinuing the license for an on-premise ERP system and starting to use the same ERP system as a service on the AWS Marketplace.

Suitable for: Projects in which there is a willingness to change the existing license model and move to an entirely new application.

Pros: Enjoy an improved feature set compared to legacy infrastructure, improved ability to leverage cloud capabilities.

Cons: Can incur major costs on the business side, the organization needs to adapt and rebuild processes around a completely new system.


  1. Refactor / Re-architect

A complete overhaul of an application to rebuild it for a cloud-native environment. 

Suitable for: Projects in which there is a strong business need to add scale, performance or features that would not be possible on-premises. 

Pros: Maximum flexibility and efficiency, push the envelope on cloud usage

Cons: The most expensive option. In many cases, it requires re-architecting and building the application or significant parts of it from scratch. It will also likely require changes to the enterprise business processes, and thus involve more testing.


  1. Retire

Identifying applications that are no longer useful and can be turned off instead of migrated to AWS. This can free up resources for applications that are actually useful and can benefit from the cloud.


  1. Retain

Some applications may not be suitable or ready for migration to the cloud. You can retain them on-premises, permanently or at least at the early stages of the migration project.

After you select a strategy and begin moving applications into AWS, you’ll discover many practical challenges. Below we briefly cover a few of the more common challenges and suggest how to deal with them. 

Migration to AWS: 5 Challenges and Solutions

Cloud migration is a complex effort, and there are many challenges you may run into in your AWS migration project. Here are a few common challenges and tips on how to resolve them.

1. Resiliency for Compute and Networking Resources


You must ensure that applications hosted on AWS are highly available and resilient. Cloud machine instances don’t live forever, so you need to find a way to preserve application state when the application moves between machine instances. In addition, you need to ensure resilient connectivity—ensuring that cloud workloads have network access at all times. 


On the compute side, you can opt for reserved instances to ensure that your machine instances stay yours for a long period of time, but this comes at a cost. Set up replication, or use a service that manages deployment and availability like Elastic Beanstalk. 

On the networking side, if you are working in a Virtual Private Cloud (VPC), Amazon provides active/standby IPSec tunnels and the AWS Direct Connect service that creates a direct connection from your enterprise network into the VPC. Use a combination of both to ensure highly resilient networking.

2. Log Analysis and Metric Collection


After migrating to AWS, you’ll find yourself in a highly scalable and dynamic environment. Your previous strategies for logging and monitoring your applications may no longer be relevant. It’s crucial to centralize data because you won’t be able to analyze a log on machine images that shut down yesterday.


Ensure that logs from applications, AWS services and S3 buckets are centrally stored and monitored. Leverage Amazon CloudWatch and see Amazon’s reference architecture for centralized logging using CloudWatch, Lambda and Cognito.

3. Managing Your Costs


Many organizations move to the cloud without establishing clear KPIs on how much they expect to spend or save after their migration. It is then difficult to understand if the migration was successful from an economic perspective. In addition, cloud environments are dynamic and costs can rapidly change as you adopt new services or scale applications up and down.


Before migrating, create a clear business case and understand how much your cloud migration should save, or how much you expect it to add to your cost, in exchange for new capabilities you don’t have on-premise. Create an economic model to simulate how much you will spend on AWS across applications, services and projects. It might be helpful to use an AWS calculator so you can more accurately plan your budget.

Like everything in life, reality will be different from your initial model, so monitor costs on an ongoing basis and identify deviations from the original cost model, investigate and resolve them before they turn into big surprises. 

4. Plan for Security


Cloud environments can be as secure as on-premise environments, but their security properties and strategies are radically different. There is a major risk of a “security vacuum”, as applications move from on-premise to the cloud, but existing security tools and strategies don’t go with them. 


Map out the security and compliance requirements of all applications in your migration project. Identify AWS services and solutions that can provide equivalent or better security measures to those you have today on-premises. And build those services into your deployment plan, ensuring that no application enters the cloud—even in development and testing phases—without the appropriate security measures. See Amazon’s cloud security guidelines. 

5. Moving On-Premise Data and Managing Storage on AWS


How do you move your data smoothly from your current on-premise location to the cloud?

  • Maintaining user experience—higher latency and insufficient bandwidth can have an adverse impact on the performance of your application.
  • Achieving resiliency—enterprises must pay attention to maintaining resiliency and high availability for data volumes on the cloud.
  • Centralized monitoring and operations—while some monitoring tools can be used for keeping tabs on data flows in AWS, this may cause fragmented visibility between on-premises and AWS environments.  


To address these challenges, enterprises should consider solutions offered by AWS, such as AWS Direct Connect, which can help them achieve highly resilient, dedicated connections between their Virtual Private Cloud (VPC) and on-premise infrastructure. This can also help synchronize your operations and create a centralized point of visibility.

You can also use Amazon CloudWatch to reduce the impact of migration on user experience. CloudWatch can help you identify performance issues in real time and address the root cause before users are affected.

Migrate to AWS Swiftly with Cloud Volumes ONTAP 

If you choose to migrate applications using the lift and shift approach, you’ll need the right tools. Many enterprises are using solution providers such as NetApp to assist them with migration and to help them with continual data management.

NetApp Cloud Volumes ONTAP is a storage management solution that offers high availability, data protection, storage efficiency features, and file services. Cloud Volumes ONTP is available on Azure, AWS and Google Cloud and supports up to a capacity of 368TB. 

Cloud Volumes ONTAP uses NetApp SnapMiror® technology, to replicate, migrate and synchronize files, or any data from on-premise, multi-cloud or hybrid storage systems architecture. 

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Want to learn more about AWS migration? 

See our additional blog posts on related topics.

Hyper-V to AWS migration strategy

Planning your migration is crucial to avoid unnecessary costs and delays. Before choosing the best approach for your migration, you need to consider questions like:

  • Are you connecting via VPN or Direct Connect?
  • How much capacity do you have and what is the current utilization?
  • How much data do you plan to move and how often does it change?
  • How much downtime will the business allow?

Read about the 5 Optimal Approaches for Your Hyper-V to AWS Migration Strategy and how to get started with your AWS migration strategy.

AWS migration strategy

There are three typical drivers for migrating applications to the cloud:

  • User agility and control
  • Scalability
  • Innovation

Amazon adapted Gartner’s 5 R model of cloud migration options to create the 6 Rs model. These options can help you move workloads to the cloud while keeping risks, time and effort to a minimum. The 6 Rs are:

  • Repurchase 
  • Replatforrm
  • Rehost
  • Refactor/ Re-Architect
  • Retire
  • Retain

Read Constructing an Effective AWS Migration Strategy for in-depth look at each approach.

AWS migration checklist

After finishing the discovery and planning phases, it is time to start the migration process. You can use a checklist to make sure you do it properly. Our AWS migration checklist includes the following steps:

  • Train staff
  • Consider security needs and access management
  • Establish cloud performance KPIs
  • Plan a database migration
  • Plan data migration for static websites and unstructured data

While there are many ways to migrate to AWS, lift and shift stands out as the quickest and most cost-effective. A successful lift and shift migration requires the right tools, and solution providers like NetApp can help you replicate, synchronize and manage your data.

Read 5 Steps to the Cloud: AWS Migration Checklist to learn more.

Bitbucket on AWS: Ultimate Quick Start Guide

Learn what is Bitbucket Data Center, and how to deploy Bitbucket on AWS. This guide includes a quick tutorial, which explains how to deploy Bitbucket on AWS using the Bitbucket Server AMI, sizing guidelines, and security considerations.

Read more: Bitbucket on AWS: Ultimate Quick Start Guide

AWS Cloud Migration Services: Don’t Migrate Alone

Amazon offers a range of migration services, some offered by Amazon itself as managed or professional services, some by Amazon partners, and some based on technological tools.

Learn about all the managed and professional services provided by AWS to help you plan your migration strategy and move workloads efficiently to the cloud.

Read more: AWS Cloud Migration Services: Don’t Migrate Alone

AWS Managed Service Provider: Passing the Baton to Certified Experts

A managed service provider (MSP) is a vendor that provides IT services for a fixed or subscription cost. MSPs enable businesses to outsource their IT tasks, scale despite staffing limitations, and reduce budgets.

AWS MSPs offer development and support for AWS services, as well as assistance with migration projects. This post reviews the cons and pros of working with an AWS MSP, and provides tips for choosing a managed service provider.

Read more: AWS Managed Service Provider: Passing the Baton to Certified Experts

AWS Storage Gateway: Connecting Your On-Premise Storage to the Amazon Cloud

The AWS Storage Gateway is a storage solution that you deploy on-premises, and allows you to integrate Amazon cloud storage with on-premise storage systems, creating a hybrid storage environment.

In this post, we’ll explain what is AWS Storage Gateway, outline the types of Gateways available and review the pricing model.

Read more in AWS Storage Gateway: Connecting Your On-Premise Storage to the Amazon Cloud

Migrating Physical Server to AWS: Now Free with AWS CloudEndure

AWS acquired CloudEndure, a Disaster Recovery as a Service (DRaaS) product that lets you seamlessly move physical server workloads to the cloud.

In this post, we’ll explain how CloudEndure works, how to install the agent on your on-premise machines to begin the AWS migration process, and explain the terms and conditions of the AWS free CloudEndure license.

Read more: Migrating Physical Server to AWS: Now Free with AWS CloudEndure

AWS Cloud Adoption Framework (CAF): 6 Migration Perspectives

Amazon Web Services (AWS) offers many benefits, including reduced costs, increased business agility, and flexibility. However, organizations often need to acquire new skills and create or update core processes before they can fully realize these benefits. Discover the AWS Cloud Adoption Framework, a structured process with 6 Perspectives and numerous Capabilities you can use to prepare your organization for the cloud.

Read more: AWS Cloud Adoption Framework (CAF): 6 Migration Perspectives

Application Migration to AWS: Free Tools to Ease Your Migration

There are many ways to migrate applications to AWS. Learn about free tools Amazon provides that can help you ease and automate application migration to AWS - for server-based applications, containers and databases.

Read more: Application Migration to AWS: Free Tools to Ease Your Migration

See Our Additional Guides on Key IaaS Topics

We have authored in-depth guides on several other topics that can also be useful as you explore the world of IaaS.

Cloud Migration

Learn about cloud migration and what major challenges to expect when implementing a cloud migration strategy in your organization. 

See top articles in our cloud migration strategy guide:


Learn what is AWS EBS and how to perform common EBS operations. Including five highly useful EBS features that can help you optimize performance and billing. 

See top articles in our guide to AWS EBS:


Learn about AWS EFS, your backup options, how to optimize performance, see a brief comparison of EFS vs EBS vs S3, and discover how Cloud Volumes ONTAP can help.

See top articles in our guide to AWS EFS:

Azure Migration

Learn about aspects of considerations when implementing Azure migration: migration models, state assessment, storage configuration, security, and maintenance. 

See top articles in our Azure migration guide:

Azure Cost Management

Learn about tools and practices that can help you manage and optimize costs on the Microsoft Azure cloud.

See top articles in our Azure cost management:

Azure High Availability

High availability is one of the major benefits of cloud services. The guarantee that your data will remain accessible is critical to supporting high priority workloads and applications and is the reason many move to the cloud in the first place.

This guide explains what high availability is and how to optimize Azure high availability.

See top articles in our Azure high availability guide:

AWS Cost Optimization

Learn how AWS cost optimization works, free Amazon tools that can help manage costs, and best practices for reducing your cloud bill.

See top articles in our AWS cost optimization guide:

AWS High Availability

Discover how high available systems are reliable and resilient and see how AWS can help you achieve high availability for cloud workloads, across 3 dimensions.

See top articles in our AWS high availability guide:

HPC on Azure

Discover services and techniques for cloud-based HPC, including unique Azure HPC features and use cases. 

See top articles in our guide to HPC on Azure:

SAP on Azure

Learn about all SAP solutions offered as a service on Azure, including HANA, S/4HANA, NetWeaver and Hybris, migration considerations and best practices.

See top articles in our guide to SAP on Azure:

Linux on Azure

Learn how to use Linux on Azure, including guides for cloud-based enterprise Linux deployments and performance tips.

See top articles in our guide to Linux on Azure:

VDI on Azure

Learn what options are available for VDI on Azure. Understand how the architecture works and discover best practices for VDI deployments.

See top articles in our guide to VDI on Azure:

AWS Big Data

Learn about the tools AWS provides for building big data infrastructure, including data lakes and big data analytics systems.

See top articles in our guide on AWS Big Data:

Google Cloud Migration

Learn how to migrate your workloads and data to Google Cloud, including in-depth comparisons between GCP and other cloud providers, tools, strategies, costs, and more.

See top articles in our guide on Google Cloud migration:

Yifat Perry, Product Evangelist

Product Evangelist