Public cloud enables users to spin up servers with a few clicks of a button. While this works great for new deployments, many organizations need to migrate existing on-premises servers into the cloud, which is a much more complex scenario. To address this issue, IT teams can use AWS Server Migration Service.
With AWS SMS, admins can automate, schedule and track the status of multiple on-premises server volumes as they replicate incrementally to AWS. This is done with a migration appliance that eliminates the need to install a migration agent on on-premises servers and enables multiple migrations to run in parallel.
AWS SMS is free; users only need to pay for the storage resource consumption.
The role of AWS SMS Connector
To set up the service, first deploy AWS SMS Connector. For now, AWS Server Migration Service only supports VMware VMs, but AWS says support for additional hypervisors is on the way.
Navigate to the AWS Server Migration Service console to download and deploy the Open Virtualization Appliance template within your VMware vSphere environment. The end result is a specialized, on-premises VM that acts as a migration appliance; this appliance is the component that makes up AWS SMS Connector.
Configure the appliance with permissions to access your AWS account. Set up an Identity and Access Management user and an IAM role that enables the connector to communicate with AWS. However, keep in mind that you will need to configure the appliance with a vCenter service account to enable the system to enumerate on-premises VMs and perform replication.
Start the replication process
Once the AWS SMS Connector appliance is up and running in your data center, you're ready to enable replication. Navigate to the AWS Server Migration Service console, which displays the appliance under the Connectors screen. From there, import the server catalog from vSphere.
The next step is to create replication jobs. Select the on-premises servers that you want to migrate to AWS. During this process, identify the license type for the VM OS. AWS SMS supports all modern versions of the Windows OS, along with Linux distributions, such as Red Hat Enterprise Linux (RHEL), SUSE/SLES, CentOS, Ubuntu, Oracle Linux, Fedora and Debian Linux. With the Windows OS, you can choose to bring your own license or pay for one from AWS. For RHEL and SUSE Linux, you'll need to bring your own license. Select these options while you create your replication jobs.
Replication jobs also include options that dictate how often changes replicate to AWS. For example, you can perform incremental replication updates for each server as frequently as every 12 hours. Server volumes maintain this incremental replication for 90 days before they are removed from AWS SMS. But you can increase this time frame via a support request. In addition, there is a limit of 50 concurrent VM migrations per account.
The appliance will create a snapshot of on-premises VMs selected within these replication jobs. This generates an Open Virtualization Format (OVF) file that ultimately uploads to Amazon Simple Storage Service. Then, the OVF file converts to an Amazon Machine Image (AMI).
Server migration and limitations to note
Once server volumes fully replicate, you can launch new Elastic Compute Cloud (EC2) instances with the AMIs that the replication jobs produced. Find these AMIs within the run history of the replication jobs in the SMS console. From there, it's as simple to launch the AMI as it is to launch instances from the EC2 console.
Pilot the use of AWS Server Migration Service to ensure it meets your needs before you commit to a large-scale migration. There are a handful of limitations that might impact the viability of the service, such as a lack of support for GUID Partition Table-based disk partitions, IPv6 addresses and multiple network interfaces on destination VMs. Review these limitations before you start a migration project.
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