EBS vs EFS | Notion

AWS Storage Options: Understanding EBS, EFS, and Instance Store

Key Differences

Feature	EBS (Elastic Block Store)	EFS (Elastic File System)	Instance Store
Storage Type	Block-level	Network File System (NFS)	Ephemeral (Temporary)
Attachment	Single EC2 instance (some exceptions)	Multiple instances across AZs	Tied to a specific EC2 instance
Availability Zones	AZ-specific	Shares data across AZs	Lost if instance terminates
Use Cases	Databases, single-instance applications	Shared file storage, web content (WordPress)	Temporary data, caching

EBS Specifics

Performance (IOPS) can be tied to volume size or configured independently (depending on volume type)
Snapshots are used for backups and cross-AZ migration
Backups can consume I/O, impacting application performance
Root volumes can be configured to persist after instance termination

EFS Specifics

Linux-only (POSIX compatible)
Typically more expensive than EBS, but offers Infrequent Access (IA) tier for cost optimization

Important Considerations

When choosing a storage solution, consider:

Data Access Pattern: Single instance vs. shared access
Persistence Needs: Will data need to outlive an instance?
Performance: Required IOPS
Cost: Balance performance requirements with budget