This page describes data migration options in Cloud SQL.

## Database Migration Service

You can migrate SQL Server databases to Cloud SQL for SQL Server
instances with Database Migration Service by using a backup and restore flow.
You first upload the full database backup and transaction
log files to a Cloud Storage bucket. Database Migration Service then actively
monitors your bucket and continuously replicates your data to the destination
Cloud SQL for SQL Server instance. For more information, see
[SQL Server migrations overview](https://docs.cloud.google.com/database-migration/docs/sqlserver/scenario-overview.md.txt) in the
Database Migration Service documentation.

## Replicate from an external server

Another option for migrating data from an external server
into Cloud SQL is to use replication.
Cloud SQL supports various replication modes
to migrate data into your instance.

For more information, see
[About replicating from an external server](https://docs.cloud.google.com/sql/docs/sqlserver/replication.md.txt).

## Limitations

- If your instance has customized backup settings (for example, a [custom backup location](https://docs.cloud.google.com/sql/docs/sqlserver/backup-recovery/backing-up#locationbackups)), then after you promote the instance, we recommend that you customize your backup settings again. During the promotion process, Cloud SQL resets your backup settings to their default values.