EBS (Elastic Block Store) and instance store are two different types of storage options available in Amazon EC2 (Elastic Compute Cloud) instances. Here are the key differences between EBS and instance store:
1. Persistence: EBS volumes offer persistent storage, meaning the data is retained even if the EC2 instance is stopped or terminated. On the other hand, instance store provides temporary storage that is tied to the lifecycle of the instance. If the instance is stopped or terminated, the data stored in the instance store is lost.
2. Durability and Redundancy: EBS volumes are replicated within an Availability Zone (AZ), providing high durability and resilience against hardware failures. In contrast, instance store is physically attached to the host instance, making it more susceptible to data loss in case of hardware failures.
3. Performance: EBS volumes offer consistent and predictable performance, and their performance characteristics can be optimized by selecting the appropriate volume type. In comparison, instance store provides higher I/O performance as it is directly attached to the host instance and doesn't rely on the network. However, the performance of instance store is not guaranteed and may vary based on the instance type.
4. Elasticity and Scalability: EBS volumes can be easily resized and attached/detached from EC2 instances, providing elasticity and scalability for storage. Instance store, on the other hand, has a fixed storage capacity determined by the instance type, and it cannot be resized.
5. Snapshotting and Backups: EBS volumes can be easily backed up by taking point-in-time snapshots, which are stored in S3. These snapshots can be used to restore or create new volumes. In contrast, instance store does not support snapshots, so alternative backup mechanisms need to be implemented.
6. Use Cases: EBS volumes are well-suited for persistent data storage, such as operating system boot volumes, databases, and file systems that require data durability. Instance store is typically used for temporary storage, caching, and scratch space where data loss is acceptable or temporary in nature.
