EC2 snapshots and RDS snapshots are two different types of snapshots offered by Amazon Web Services (AWS) for data protection and recovery. Here are the key differences between them:
Service: EC2 snapshots are associated with Amazon Elastic Compute Cloud (EC2), which provides virtual servers in the cloud. RDS snapshots, on the other hand, are associated with Amazon Relational Database Service (RDS), a managed database service in AWS.
Scope: EC2 snapshots capture the state of an entire EC2 instance, including the root volume and any additional attached volumes. They can be used to back up both the operating system and data stored on the instance. RDS snapshots, however, are focused on backing up and restoring RDS database instances and their associated storage volumes. They specifically capture the database engine, configuration, and data.
Application Consistency: EC2 snapshots can be taken while an instance is running, but they might not guarantee application consistency since they are block-level snapshots of the instance's volumes. For ensuring application consistency, you might need to take additional steps like freezing the file system or using database-specific techniques. RDS snapshots, on the other hand, ensure application consistency by coordinating with the specific database engine and performing the necessary actions to ensure data integrity.
Backup Frequency: EC2 snapshots are typically taken manually or scheduled at the discretion of the user. You have control over when and how often you create the snapshots. RDS snapshots, on the other hand, can be automated using the backup functionality provided by RDS. You can configure automated backups to occur daily, and the retention period can be set to keep a specific number of backups.
Storage: EC2 snapshots are stored in Amazon Simple Storage Service (S3), a scalable object storage service. They can be copied across regions and accounts, enabling portability and disaster recovery. RDS snapshots, by default, are stored in Amazon S3 as well, but you don't have direct access to them. Instead, you manage RDS snapshots through the RDS service and can restore them directly into RDS instances.
Restore Process: To restore an EC2 snapshot, you create a new EC2 instance from the snapshot, specifying the appropriate volume configurations. The new instance will have the data and configuration of the original instance at the time the snapshot was taken. Restoring an RDS snapshot involves creating a new RDS instance from the snapshot, specifying the desired database engine, instance type, and other configurations. The new RDS instance will have the database and its data as it existed at the time the snapshot was taken.
Both EC2 snapshots and RDS snapshots serve as valuable backup and recovery mechanisms, but they differ in their focus on virtual machine instances and databases, respectively, as well as the level of automation and application consistency they provide.
