How to migrate the SQL server SSAS to AWS RDS SQL Server

Whether you decide to use SQL Server on EC2 or RDS I you can use SQL Server Management Studio (SSMS) to backup the SSAS database on the source server and then transfer that backup to ec2 or RDS via s3.

Microsoft has some good instructions here on migrating SSAS to a new server: https://learn.microsoft.com/en-us/sql/database-engine/install-windows/upgrade-analysis-services?view=sql-server-ver15#side-by-side-upgrade

Note: the difference with SSAS running on RDS SQL Server is that instead of using SSMS to restore the database you will need to use RDS specific stored procedures:

e.g. exec msdb.dbo.rds_msbi_task

Here is a good blog with details on backup and restoring an SSAS database on RDS: https://aws.amazon.com/blogs/database/configuring-microsoft-sql-server-analysis-services-on-amazon-rds-for-sql-server/