What is the difference between EBS and instance store?
AWS · Intermediate level
Answer
EBS is persistent block storage attached to EC2 and can survive stop/start or termination if configured. Instance store is local ephemeral storage lost on stop, termination, or host failure, so it is only for rebuildable temporary data.
Technical explanation
EBS is AZ-scoped persistent block storage; instance store is host-local and ephemeral.
AWS storage choices are based on access model: block storage for disks, object storage for objects, shared file storage for POSIX file access, and ephemeral storage for rebuildable temporary data.
Performance must be evaluated at both the storage layer and instance/network layer; a high-performance volume cannot exceed instance bandwidth limits.
Backups are only useful when restore is tested, retention is aligned to policy, and encryption/cross-account/cross-Region protection is considered.
Hands-on example
1. Provision the storage option in a test environment with encryption, tags, backups, and monitoring enabled.
2. Run a workload-specific benchmark for IOPS, throughput, latency, concurrency, or shared-file behavior.
3. Create and restore a backup or snapshot to prove recovery rather than only creation.
4. Document the selected storage type, limits, cost assumptions, and restore runbook.
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