Comparison of EBS, EFS, and Instance Store in AWS
🧱 1. EBS (Elastic Block Store)
| Feature | Description |
|---|---|
| Type | Block Storage |
| Attachable To | One EC2 instance at a time (per volume) |
| Persistence | Yes – data survives instance stop/start/terminate |
| Use Case | Boot volumes, databases, file systems |
| Performance | SSD (gp3, io2) or HDD (st1, sc1) options |
| Scalability | Up to 64 TiB per volume |
| Backup | Snapshots to S3 supported |
| Pricing | Pay for provisioned GB/month |
✅ Analogy: Like an external hard drive plugged into your EC2.
📂 2. EFS (Elastic File System)
| Feature | Description |
|---|---|
| Type | Network File Storage (NFS) |
| Attachable To | Multiple EC2 instances (Linux only) |
| Persistence | Yes – highly durable and available |
| Use Case | Shared file systems, containerized workloads, CMS |
| Performance | Scales automatically, burstable |
| Scalability | Virtually unlimited |
| Backup | Automatic backups + point-in-time recovery |
| Pricing | Pay per GB used (not provisioned) |
✅ Analogy: Like a shared drive mounted over the network.
⚡ 3. Instance Store (Ephemeral Storage)
| Feature | Description |
|---|---|
| Type | Direct-attached NVMe or SSD |
| Attachable To | Specific EC2 instance types only |
| Persistence | ❌ No – data is lost if instance stops/terminates |
| Use Case | Temporary storage, cache, buffers, scratch data |
| Performance | Very fast – local disk speed |
| Scalability | Limited to instance type |
| Backup | Not supported |
| Pricing | Included in EC2 price (no extra charge) |
✅ Analogy: Like a temporary notepad on your desk — fast but wiped if you shut down.
🧠 TL;DR Comparison Table:
| Feature | EBS | EFS | Instance Store |
|---|---|---|---|
| Type | Block storage | File storage (NFS) | Temporary block storage |
| Persistence | ✅ Yes | ✅ Yes | ❌ No |
| Multi-Instance Access | ❌ No | ✅ Yes | ❌ No |
| Performance | Good to High (SSD/HDD) | Auto-scaling, shared | Very high (local disk) |
| Backup | ✅ Snapshots | ✅ Automatic | ❌ Not supported |
| Ideal For | Boot volumes, DBs | Shared config/code | Cache, temp processing |