AWS Migration with AWS Server Migration Service

  • 3 min read

Server Migration Service (SMS) from AWS is an agentless service that enables customers to simplify the AWS Migration process by automatically replicating live server volumes from their on premises servers in to AWS.  AMIs (Amazon Machine Images) are automatically created from the replicated volumes, which can be used to launch the servers as AWS EC2 instances.  SMS can be used to migrate live running server instances from VMware, HyperV and Microsoft Azure environments.

How does AWS Server Migration Service Work?

AWS Server Migration Service can be accessed via the AWS Console.  SMS has a downloadable FreeBSD virtual appliance – the Server Migration Connector – in OVA (Open Virtual Appliance) format for VMware deployments, and VHD (Virtual Hard Disk) appliance for Microsoft HyperV. A Powershell setup script is also available for Microsoft Azure environments.

Once the Server Migration Connector has been configured and give the necessary access accounts (IAM role in AWS, vCenter Service Account, WinRM user in System Center Virtual Machine Manager and roles & permissions for Azure) it can be viewed on the SMS connectors page.

Users can then import a server catalogue from the on premises environment. Next, replication jobs can be set up to begin replicating the server volumes into AWS.  SMS creates an encrypted S3 bucket in the chosen region with a bucket policy which automatically deletes objects after 7 days.  The server volumes are replicated to the S3 bucket, and SMS then creates EBS (Elastic Block Store) snapshots from the replicated volumes. The EBS snapshots can be be encrypted.

In addition to replicating single servers, SMS users have the option to configure Application Migration groups – logical groupings of servers used to support a specific application.  SMS Application Migration replicates all servers in an application as AMIs, then creates a CloudFormation template to co-ordinate the launch of the AMIs.  Applications can be subdivided into groups which can be used for application tiers – eg Web, App, & Database tiers.  The CloudFormation template can be configured to launch the tiers in the appropriate order for the application to come up gracefully when launching in AWS.

SMS allows customers to replicate up to 50 virtual machines per account simultaneously – a higher limit can be requested.  Replication jobs can run for 90 days per VM after which they are terminated unless the customer requests a limit increase.

What does AWS Server Migration Service cost?

AWS Server Migration Service is itself free to use, but customers do incur costs for:

  • Volume Images stored in the S3 Bucket
  • EBS Snapshot Storage
  • Data Transfer used in the migration process
  • Any EC2 instances launched 

Server Migration Service Or CloudEndure?

You may be wondering what the difference is between SMS and CloudEndure.  Both are AWS services which can be used to replicate server workloads into the AWS Cloud.  Both are free to use for 90 days.

CloudEndure is an agent based service – it can be used to replicate any type of server into AWS – Virtual machine or bare metal.  If you have bare metal servers, you’ll definitely need to use CloudEndure.

AWS Server Migration Service is only suitable for virtual machine migrations from VMware, HyperV and Azure.  So if you are migrating VMs only, SMS offers a simpler, agentless solution for your AWS migration.


Karl Robinson

Director and Co-Founder of Logicata, an AWS Managed Services Provider. Over 20 years experience in the internet & cloud industry. Closet geek, AWS & Azure certified.