📖 What is Block Storage?
Block storage divides data into equally-sized blocks, offering low-latency, direct access ideal for operating systems, databases, and applications requiring rapid data retrieval. Unlike object storage, it presents a volume as a raw, unformatted device to the operating system. Amazon EBS is AWS’s primary block storage service.
"Understand the distinction between block, object, and file storage. Exam questions frequently present scenarios requiring you to select the appropriate storage type based on performance, cost, and access patterns. Focus on EBS volume types (SSD vs. HDD) and their use cases. Be prepared to identify scenarios where block storage is superior to object storage."
📚 Certification: AWS Certified Cloud Practitioner (CLF-C02)
🔑 What are the Key Concepts of Block Storage?
- ▸ Block storage provides low-latency access, making it suitable for workloads like databases and virtual machines needing fast, consistent performance.
- ▸ Amazon EBS volumes are attached to EC2 instances, functioning like a physical hard drive for the operating system and applications.
- ▸ Different EBS volume types (e.g., gp3, io2, st1, sc1) offer varying price/performance characteristics to optimize for specific workloads.
- ▸ Block storage is typically more expensive per GB than object storage but delivers superior performance for random read/write operations.
- ▸ EBS volumes can be encrypted at rest and in transit, enhancing data security and meeting compliance requirements.
🎯 How does Block Storage appear on the CLF-C02 Exam?
You may be asked to identify the best storage option for a database server requiring high IOPS and low latency, comparing EBS to S3.
A scenario might describe an application needing consistent, high-performance storage for a virtual desktop infrastructure (VDI) – determine the appropriate EBS volume type.
Expect questions about choosing between different EBS volume types based on cost and performance needs for a specific application workload.
❓ Frequently Asked Questions
When would I choose a provisioned IOPS EBS volume (like io2) over a general purpose volume (like gp3)?
Provisioned IOPS volumes are ideal for databases or applications demanding consistently high IOPS, even during peak loads. gp3 offers a good balance of cost and performance for most workloads.
Can I resize an EBS volume while an instance is running?
Yes, you can generally increase the size of an EBS volume while the instance is running, but decreasing the size may require detaching the volume. Always check the AWS documentation for the latest limitations.
What happens to my data on an EBS volume if the EC2 instance it's attached to is terminated?
By default, data on EBS volumes is *not* automatically deleted when an EC2 instance is terminated. However, the volume's attachment is removed, and you'll continue to be charged for its storage until you explicitly delete it.