Step 7: Create an Amazon DMS Replication Instance - Database Migration Guide
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Step 7: Create an Amazon DMS Replication Instance

After we validate the schema structure between source and target databases, as described preceding, we proceed to the core part of this walkthrough, which is the data migration. The following illustration shows a high-level view of the migration process.

Migration process

A DMS replication instance performs the actual data migration between source and target. The replication instance also caches the transaction logs during the migration. How much CPU and memory capacity a replication instance has influences the overall time required for the migration.

To create an Amazon DMS replication instance, do the following:

  1. Sign in to the Amazon Web Services Management Console, select Amazon Database Migration Service (Amazon DMS) and choose Create replication instance. If you are signed in as an Amazon Identity and Access Management (IAM) user, you must have the appropriate permissions to access Amazon DMS. For more information about the permissions required, see IAM Permissions.

  2. On the Create replication instance page, specify your replication instance information as shown following.

    For This Parameter Do This


    Enter DMSdemo-repserver.

    Descriptive Amazon Resource Name (ARN)

    Skip this optional field.


    Enter a brief description, such as DMS demo replication server.

    Instance class

    Choose dms.t3.medium. This instance class is large enough to migrate a small set of tables.

    Engine version

    Choose 3.4.5. This is the latest Amazon DMS version, which includes all new features and enhancements.

    Allocated storage (GiB)

    Choose 50. This storage space is enough for your migration project.


    Choose DMSDemoVPC, which is the VPC that was created by the Amazon CloudFormation stack.


    Choose Dev or test workload (Single-AZ).

    Publicly accessible

    Leave this item selected.

  3. For the Advanced, Maintenance, and Tags sections, leave the default settings as they are, and choose Create.