EBS Review

Amazon Elastic Block Store: A Comprehensive Guide

Amazon Elastic Block Store (EBS) is a high-performance block storage service designed to work with Amazon EC2 instances, providing reliable and persistent storage. Whether you need storage for a small database, a large-scale enterprise application, or anything in between, EBS offers a scalable and flexible solution.

Key Features of Amazon EBS

• Persistent Storage: EBS provides persistent storage that can be attached to EC2 instances both before and after runtime. By default, EBS volumes are terminated when the EC2 instance is deleted, though this can be adjusted.
• Scalability: EBS volumes can scale from gigabytes to terabytes, allowing you to increase capacity anytime to match application requirements.
• High Availability and Durability: EBS volumes are automatically replicated within their availability zone to protect against hardware failure, ensuring high availability and durability.
• Data Protection and Recovery: Snapshots can be taken of EBS volumes and stored in Amazon S3 to ensure data durability and facilitate disaster recovery.
• Security: EBS supports encryption at rest and in transit, ensuring data security and compliance with regulations.

Best Practices for Using Amazon EBS

1. Snapshot Management: Regularly create snapshots of your EBS volumes to ensure data backup and enable quick recovery.
2. Performance Tuning: Select the appropriate EBS volume type based on your application’s performance requirements. For high IOPS needs, use Provisioned IOPS SSD (io1) volumes.
3. Monitoring and Optimization: Utilize Amazon CloudWatch metrics to monitor EBS performance and set alarms for key metrics such as latency, throughput, and IOPS.
4. Security: Enable encryption for EBS volumes containing sensitive data to ensure compliance with security policies and regulations.

Understanding Amazon Machine Images (AMIs)

AMIs are region-specific and cannot be used to launch EC2 instances in other AWS Regions directly. However, you can copy an AMI to the target region and then use it to create EC2 instances.

Practice Questions for EBS

To help you prepare for the AWS Certified Developer Associate exam, here are some practice questions related to Amazon EBS:

1. What is Multi Attach?

   • Answer: Attaching the same EBS volume to multiple EC2 instances in the same Availability Zone.

2. You are running a database workload on an EC2 instance with an EBS volume attached. The database frequently writes large amounts of data. Which EBS volume type should you choose to optimize performance for this use case?

   • A) General Purpose SSD (gp2)
   • B) Provisioned IOPS SSD (io1)
   • C) Throughput Optimized HDD (st1)
   • D) Cold HDD (sc1)
   • Correct Answer: B) Provisioned IOPS SSD (io1)

3. You need to take a point-in-time snapshot of your EBS volume for backup purposes. How can you ensure that the data is consistent when the snapshot is created?

   • A) Stop the EC2 instance before taking the snapshot
   • B) Create the snapshot directly from the EBS volume
   • C) Use EBS multi-volume snapshots
   • D) Use Amazon Data Lifecycle Manager to create snapshots
   • Correct Answer: A) Stop the EC2 instance before taking the snapshot

4. You have an application that requires high IOPS performance. How can you increase the IOPS provisioned for your EBS volume?

   • A) Modify the volume type from gp2 to io1
   • B) Take a snapshot of the volume and restore it as an io1 volume
   • C) Enable EBS volume modification to change the IOPS
   • D) Increase the size of the EBS volume
   • Correct Answer: B) Take a snapshot of the volume and restore it as an io1 volume

5. You need to encrypt an existing unencrypted EBS volume. What is the recommended approach?

   • A) Enable encryption on the existing volume
   • B) Create a snapshot of the unencrypted volume and copy it as an encrypted volume
   • C) Detach the volume, enable encryption, and re-attach it
   • D) It is not possible to encrypt an existing unencrypted EBS volume
   • Correct Answer: B) Create a snapshot of the unencrypted volume and copy it as an encrypted volume

Explanations

1. For database workloads with large writes, use Provisioned IOPS SSD volumes to achieve consistent high performance.
2. To ensure data consistency when creating EBS snapshots, stop the EC2 instance first to flush all data from memory to disk.
3. You cannot modify the IOPS of an existing volume. To increase IOPS, take a snapshot and restore it as an io1 volume with the desired IOPS.
4. You cannot enable encryption on an existing unencrypted volume. Create a snapshot and copy it as a new encrypted volume.

By following these best practices and understanding the intricacies of Amazon EBS, you can optimize your cloud storage strategy to ensure performance, reliability, and security for your applications.

EBS Table

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Elastic Instance Store has the best performance highest I/O but is ephermal