03. 💾 EC2 Instance Store
The network attached drive EBS have a latency issue, it's goood but limited in perfomance.
The EC2 Instance Store provides temporary block-level storage that is physically attached to the host server running your EC2 instance. It delivers very high I/O performance and low latency, making it ideal for workloads that require fast, transient data access.
| Feature | Description |
|---|---|
| Type | Ephemeral (temporary) block storage |
| Attached To | Physical host server hardware |
| Performance | Extremely high I/O throughput |
| Persistence | Lost when instance stops, terminates, or host fails |
| Use Cases | Caching, buffers, temporary data, scratch space |
⚙️ How It Works
When you launch a specific EC2 instance type (like the I3, I4i, or D2 families),
AWS attaches Instance Store volumes that reside on disks physically connected to the host computer.
Unlike EBS (Elastic Block Store), which is network-attached and persistent,
the Instance Store is local to the machine — providing much faster disk performance.
⚠️ Important: Data on Instance Store is lost if:
- The instance stops or terminates
- The underlying hardware fails
🚀 Performance
| Storage Type | Example Instance | Read IOPS | Write IOPS |
|---|---|---|---|
| Instance Store (I3) | i3.16xlarge | 3.3 million | 1.4 million |
| EBS (gp2) | General Purpose SSD | ~32,000 | ~32,000 |
As seen above, Instance Store provides magnitudes higher performance than EBS volumes.
🧠 Use Cases
| Scenario | Why Instance Store Works Best |
|---|---|
| Cache / Buffer storage | High-speed, temporary data access |
| Scratch / Temp space | Short-lived data used during processing |
| High-performance DB caching | Fast reads/writes without persistence need |
| Big data / analytics workloads | Fast local read/write operations |
⚠️ Limitations
- ❌ Data is not persistent (lost on stop/termination)
- ❌ Cannot be detached or reattached to another instance
- ⚠️ You are responsible for backups and data replication if needed
- 📦 Not available on all instance types
🧾 Summary
| Feature | Instance Store | EBS Volume |
|---|---|---|
| Storage Type | Local physical disks | Network-attached disks |
| Performance | Extremely high | High (depends on type) |
| Persistence | Ephemeral | Persistent |
| Backup Responsibility | User-managed | AWS-managed (snapshots) |
| Typical Use Case | Cache, temp data, scratch space | Long-term data storage |
🧠 Key Exam Tip
Whenever you see:
"High-performance, low-latency storage" or "ephemeral storage attached to EC2"
➡️ Think EC2 Instance Store — not EBS.