EC2 Instance Store is a type of temporary block-level storage that is physically attached to the host computer where your EC2 instance runs. This storage option provides high-performance local storage with very low latency because the disks are connected to the same physical server as your instance…EC2 Instance Store is a type of temporary block-level storage that is physically attached to the host computer where your EC2 instance runs. This storage option provides high-performance local storage with very low latency because the disks are connected to the same physical server as your instance.
Key characteristics of EC2 Instance Store include:
1. **Ephemeral Nature**: Instance store data is temporary. When you stop, terminate, or if the underlying host fails, all data on the instance store is lost. This makes it unsuitable for data that needs to persist beyond the instance lifecycle.
2. **High Performance**: Because the storage is physically attached to the host, instance stores offer extremely fast I/O operations. They are ideal for temporary data like buffers, caches, scratch data, and other temporary content.
3. **No Additional Cost**: Instance store volumes are included in the cost of the EC2 instance itself. You do not pay separately for this storage.
4. **Fixed Size**: The size and number of instance store volumes available depend on the EC2 instance type you choose. Not all instance types include instance store volumes.
5. **Use Cases**: Instance stores are best suited for temporary storage needs such as temporary processing files, cache storage, buffer storage, and data that is replicated across multiple instances.
In contrast to Amazon EBS (Elastic Block Store), which provides persistent storage that remains available even after stopping an instance, instance store should only be used for data you can afford to lose.
When planning your architecture, consider using instance store for high-speed temporary storage requirements while relying on EBS or S3 for persistent data storage needs. Understanding when to use instance store versus other storage options is essential for both cost optimization and application reliability in AWS environments.
EC2 Instance Store: Complete Guide for AWS Cloud Practitioner Exam
What is EC2 Instance Store?
EC2 Instance Store, also known as ephemeral storage, is a type of temporary block-level storage that is physically attached to the host computer where your EC2 instance runs. This storage consists of disks that are directly connected to the underlying hardware of the instance.
Why is EC2 Instance Store Important?
Understanding Instance Store is crucial because:
• It provides the highest possible I/O performance for your EC2 instances • It offers no additional cost - the storage is included with certain instance types • It helps you understand the difference between persistent and non-persistent storage in AWS • It's a common topic in AWS certification exams
How EC2 Instance Store Works
Instance Store operates with the following characteristics:
1. Temporary Nature: Data on instance store volumes is lost when the instance is stopped, terminated, or if the underlying hardware fails. This is why it's called ephemeral storage.
2. Physical Attachment: The storage is physically attached to the host machine, providing extremely low latency and high throughput compared to network-attached storage like EBS.
3. Instance Type Dependency: Not all EC2 instance types include instance store. Only specific instance families (like i3, d2, c5d, m5d) come with instance store volumes.
4. No Replication: Data is not replicated across multiple devices. If the disk fails, the data is lost.
5. Cannot Be Detached: Unlike EBS volumes, instance store volumes cannot be detached and attached to another instance.
Best Use Cases for Instance Store:
• Temporary data processing • Buffers and caches • Scratch data • Data that is replicated across multiple instances • High-performance computing requiring fast local storage
Instance Store vs. EBS - Key Differences:
• Persistence: EBS is persistent; Instance Store is temporary • Performance: Instance Store offers higher IOPS for certain workloads • Cost: Instance Store is included; EBS has separate charges • Flexibility: EBS can be detached; Instance Store cannot
Exam Tips: Answering Questions on EC2 Instance Store
Tip 1: When you see keywords like ephemeral, temporary storage, or highest I/O performance, think Instance Store.
Tip 2: If a question mentions data that must survive instance termination or stopping, Instance Store is NOT the correct answer - choose EBS or S3 instead.
Tip 3: For scenarios requiring buffer storage, cache, or scratch space where data loss is acceptable, Instance Store is likely the answer.
Tip 4: Remember that Instance Store data is lost when: • The instance is stopped • The instance is terminated • The underlying disk drive fails • The instance hibernates
Tip 5: If a question asks about storage that comes at no extra cost with certain instance types, Instance Store is the answer.
Tip 6: Questions about physically attached storage or local storage on EC2 are referring to Instance Store.
Tip 7: For questions about high-performance temporary workloads or applications that need extremely low latency local storage, Instance Store is typically correct.
Common Exam Question Patterns:
• A company needs temporary storage for processing large datasets with high I/O requirements - Answer: Instance Store • Which storage option provides the fastest possible read/write speeds for an EC2 instance? - Answer: Instance Store • A developer needs persistent storage that survives instance termination - Answer: EBS, NOT Instance Store