DB Snapshots and Migration with RDS

DB snapshots

DB snapshots are user-initiated and enable you to back up your DB instance in a known state as frequently as you wish and then restore to that specific state. However, they cannot be used for point-in-time recovery.

• You can restore up to the last 5 minutes.
• Snapshots can be shared with other AWS accounts.
• Snapshots are stored on S3 and remain on S3 until manually deleted.
• Backups are taken within a defined window. I/O is briefly suspended while backups initialize and may increase latency (applicable to single-AZ RDS).
• DB snapshots that are performed manually will be stored even after the RDS instance is deleted.

Limitations

You cannot restore from a DB snapshot to an existing DB;a new instance is created when you restore. Restored DBs will always be a new RDS instance with a new DNS endpoint.

Only default DB parameters and security groups are restored; you must manually associate all other DB parameters and SGs.

Recommendation

It is recommended to take a final snapshot before deleting an RDS instance.