We’ll now talk through how to restore a database from a snapshot. This process creates a new database that will retain a majority of the configuration of the database that the snapshot was taken from.

You’ll need the following pieces of information:

• The ID of the snapshot you wish to restore from
• A name or identifier that you wish to give to the database we’re about to create

Follow these steps to restore an RDS snapshot:

1. Type the following command:

      aws rds restore-db-instance-from-db-snapshot \
        --db-snapshot-identifier <name-of-snapshot-to-restore > \
        --db-instance-identifier <name-for-new-db> \
        --db-subnet-group-name <your-db-subnet-group> \
        --multi-az

2. You may have noticed that this command creates a new database in the default security group. This happens because restore-db-instance-from-db-snapshot doesn’t accept a security group ID as a parameter. You’ll have to run a second command to assign a non-default security group to the new database:

      aws rds modify-db-instance \
        --db-instance-identifier <name-of-newly-restored-db> \
        --vpc-security-group-ids <id-of-security-group>

RDS backups use the snapshot process to make a copy of the entire database instance, not just individual databases or schemas. When restoring the snapshot, you must create a new instance instead of restoring to the original instance. Be sure to associate the restored instance with the original parameter group so that the correct settings are applied to the instance. 

The restore-db-instance-from-db-snapshot command includes the parameter for enabling multi-AZ on the new DB. If you’d like the new DB to be running in single-AZ mode only, then can you simply remove this flag.