Migrating to the cloud involves several steps and can be a challenge for any enterprise unless you’ve a trustworthy orchestrator to automate, schedule, reduce data migration cutover time and to minimize the bandwidth consumption for replicated data.  AWS Server Migration Service (SMS) is one such service that will make your migration process easier. This article will demystify how this works and why it could be the best option for your subsequent migration.

What is AWS Server Migration Service?

AWS SMS is an agentless service that makes virtual migration easy from any on-premises server to AWS. SMS automates all the steps required to migrate an on-premises server to Amazon EC2, including servers running Windows and Linux operating systems. You can move a live server to Amazon EC2 with no downtime using SMS. It also supports migration from Amazon EC2 instances from one Availability Zone to another. SMS automates the process of converting your existing server images to Amazon Machine Images (AMIs) and then launching new Amazon EC2 instances with those AMIs. SMS also handles all the necessary configuration changes and data replication tasks so that your migrated servers are ready to run in AWS. Moreover, it manages and tracks the progress of server migration with a user-friendly UI.

Let’s take a closer look at how SMS works and how you can leverage it to migrate your on-premise servers to AWS. We’ll also discuss some key benefits of using SMS for server migration.

How Does AWS Server Migration Service Work?

As AWS SMS does not have an agent, replication of on-premise servers to AWS becomes hassle-free. SMS can migrate virtual servers, physical servers, virtual machines (VMs), cloud instances and it also supports a broad range of source as well as destination servers. You can be confident that your server migrations will be quick and seamless because it’s built on reliable and low-latency AWS infrastructure. This allows you to speed up your workflow and adopt an agile approach to your server migrations. At the core, SMS automates the migration of 3 common virtual machines including VMware vSphere, Microsoft Hyper-V/SCVMM, and Azure virtual machines.  

Essentially, you install the SMS Migration Connector on your on-premise servers. This connector uses the Amazon EC2 API to initiate replication of your server volumes to Amazon S3. Once the data is in Amazon S3, SMS creates an Amazon Machine Image and then launches replacement instances from that AMI. You can use SMS to schedule periodic replication of your on-premise servers to always have an up-to-date backup in AWS. You can also use SMS to perform one-time migrations of servers, for example, when moving to a new data center.

It’s easy to use and provides a high degree of flexibility in terms of what you can migrate, when you migrate and how often you migrate, proving highly beneficial to any enterprise.

Benefits of AWS Server Migration Service

AWS service automates the entire replication process, making it effortless to move your servers to the cloud with minimal disruption. You can replicate your whole on-premise server environment, including applications, databases, and configurations, to AWS with just a few clicks. The service is designed to be simple and cost-effective, so you can efficiently migrate your servers to AWS without incurring significant infrastructure costs.  

There are several advantages to using SMS for server migrations:

  • Ease of use: SMS takes care of all the difficult work involved in migrating your servers. You only have to install the SMS Connector on your on-premise servers and then specify which servers you want to migrate. SMS handles all the heavy lifting involved in migrating your servers, making it a smooth transition to AWS.
  • Minimized downtime: You can schedule when replication occurs so that there is minimal downtime during the actual migration process.
  • Cost savings: Migrating to AWS can save you money on your overall infrastructure costs. AWS also offers a pay-as-you-go platform, so you only pay for the resources you use. It can be a significant saving compared to maintaining your own on-premise servers.

Few things to keep in mind before opting for SMS migration are listed below to help you take an informed decision:

  • Is your infrastructure dependent on conventional VMs?
  • The VMs should be among the 3 classic supported VMs
  • Are you lifting and shifting or refactoring?
  • Are you looking for partial or complete migration?


With SMS, the final output is an Amazon Machine Language. There will be an AMI for each replication run until the process is complete/deleted by you/after 90 days, whichever is first achieved. Each replication cycle has a minimum of 12 and a maximum of 24 hours. You can also access the details of all the replication cycles using the ‘get-replication-jobs’ command.

Migrating your servers to AWS can be daunting, but with the right tools and planning, it doesn’t have to be. You can easily migrate your data with zero to minimal downtime by leveraging the S3 bucket replication feature.

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