AWS-RDS SQL Server limitations

Migrating from on-premises to AWS RDS SQL Server, requires analysis of the existing on-premises set up and identify opportunities to modernize.

The limitations listed below are supplied by AWS  , but there are other architectural considerations:

A sample list would include :

1) Should another Cloud DBMS platform be used?

2) High Availability requirements 

3)Disaster Recovery requirements 

4)ecryption and management of sensitive data in the Cloud 

Some AWS  RDS SQL Server limitations

- Some ports are reserved for Amazon RDS, and you can't use them when you create a DB instance.

- Amazon RDS for SQL Server doesn't support importing data into the msdb database.

- You can't rename databases on a DB instance in a SQL Server Multi-AZ deployment.

-  AWS RDS doesn't support Data Quality Services and Master Data Services on the same RDS service, need to spin up an EC2 and run services form another server

-The maximum storage size for SQL Server DB instances is the following:

-> General Purpose (SSD) storage – 16 TiB for all editions

->Provisioned IOPS storage – 16 TiB for all editions

-> Magnetic storage – 1 TiB for all editions

SQL Server security limitations

The following server-level roles aren't available in Amazon RDS for SQL Server:

The following server-level permissions aren't available on RDS for SQL Server DB instances:

Limits of databases on database instances for a Single-AZ- depends on instance class type

db.*.micro to db.*.medium   30 

db.*.large   30 

db.*.xlarge to db.*.16xlarge  100

db.*.24xlarge              100

Features not supported and features with limited support

The following Microsoft SQL Server features are not supported on Amazon RDS:

The following Microsoft SQL Server features have limited support on Amazon RDS:

AWS SQL Server Backup & Restore limitations

- You can't restore a snapshot from a DB instance in one time zone to a DB instance in a different time zone.If you restore a backup file from one time zone to a different time zone, you must audit your queries and applications for the effects of the time zone change

- You can't back up to, or restore from, an Amazon S3 bucket in a different AWS Region from your Amazon RDS DB instance.

- You can't restore a database with the same name as an existing database. Database names are unique.

- Amazon S3 has a size limit of 5 TB per file. For native backups of larger databases, you can use multifile backup.

- You can't back up to or restore from more than 10 backup files at the same time.

 - A differential backup is based on the last full backup. For differential backups to work, you can't take a snapshot between the last full backup and the differential backup. If you want a differential backup, but a manual or automated snapshot exists, then do another full backup before proceeding with the differential backup.

 - You can't perform native log backups from SQL Server on Amazon RDS.

-You can create native backups of Transparent Data Encryption (TDE)-enabled databases, but you can't restore those backups to on-premises databases. You can't restore native backups of TDE-enabled, on-premises databases.

-You can't back up a database during the maintenance window, or any time Amazon RDS is in the process of taking a snapshot of the database.

For the most up to date information on AWS RDS SQL Server check Amazon RDS for Microsoft SQL Server