AWS EBS Interview Q/A

1. What is an Elastic Block Store?
   Amazon Elastic Block Store (EBS) is a block storage system that provides highly available block-level storage volumes for use with Amazon EC2 instances. It offers three types of volumes: General Purpose (SSD), Provisioned IOPS (SSD), and Magnetic. These volumes differ in terms of performance, characteristics, and cost. EBS is designed for use with EC2 instances and is suitable for a wide range of workloads, including both throughput and transaction-intensive applications.

2. Why is Amazon EBS Useful?
   Amazon EBS is useful because it provides persistent block storage volumes that can be attached to Amazon EC2 instances. It offers various storage performance and cost options, making it suitable for a wide range of applications and workloads.

3. What are the benefits of Amazon EBS?

   • Reliable and secure storage: EBS volumes automatically respond to their Availability Zone to protect against component failure.

   • Secure: Access control policies allow you to specify who can access EBS volumes, enhancing data security.

   • Higher performance: EBS uses SSD technology to deliver consistent I/O performance for applications.

   • Easy data backup: Point-in-time snapshots of EBS volumes make data backup and recovery simple.

4. What are the various types of EBS volumes?
   Amazon EBS offers five types of volumes:

   • General Purpose SSD (gp2)

   • Provisioned IOPS SSD (io1)

   • Throughput Optimized HDD (st1)

   • Cold HDD (sc1)

   • Magnetic (standard)

5. What can I expect from Amazon EBS volumes in terms of performance? Amazon EBS offers different volume types with varying levels of performance and cost, allowing you to choose the right storage for your applications. The typical latency between EC2 instances and EBS is in the single-digit milliseconds.

6. What is a block storage volume?
   A block storage volume functions similarly to a hard drive and can be used to store any type of file or even an entire operating system. EBS volumes are placed in an availability zone and automatically replicated to protect against data loss in case of a single component failure.

7. How do you make an EBS volume available with no downtime and attach it to an EC2 instance when it fails?
   You can achieve this by using a load balancer and auto-scaling. When an EBS volume fails, you can replace it with the most recent backup or snapshot to minimize downtime.

8. What is the maximum size of an EBS storage device?
   The maximum volume size supported by EBS is 16 TiB. However, the actual recognized capacity may depend on the operating system's characteristics and volume partitioning.

9. What is Amazon Machine Images (AMI) in AWS?
   An Amazon Machine Image (AMI) contains all the information required to launch an instance in AWS. When launching an instance, you specify an AMI to define the instance's configuration and software.

10. What are the different kinds of EBS Volumes?
    EBS volumes include General Purpose EBS (SSD), IOPS provisioned (SSD), and Magnetic Volumes (formerly known as standard volumes), each designed for specific use cases.

11. Is it necessary to unmount volumes before taking a snapshot?
    While snapshots can be taken without unmounting a volume, it's recommended to ensure data consistency by cleanly unmounting the volume before taking a snapshot.

12. How do you transfer files from one EBS to another?
    To transfer files between EBS volumes, you can attach both volumes to an instance, copy the files, and then detach the volumes once the transfer is complete.

13. What happens to data when an Amazon EC2 instance is terminated?
    Data stored on an Amazon EBS volume persists independently from the instance's lifetime. It is recommended to use EBS volumes or backup data to Amazon S3 for durability, especially when using an EBS volume as a root partition.

14. How can you list information about AWS volumes?
    You can use the command aws ec2 describe-volumes with a query to list information about AWS volumes.

15. How to attach an external disk to an AWS cluster Kubernetes?
    You can use a PersistentVolume (PV) definition that references an AWS Elastic Block Store (EBS) volume by specifying the volume ID. This PV can then be used by Kubernetes pods.

16. What is an EBS block device?
    An EBS block device mapping specifies which block devices, including instance store volumes and EBS volumes, are associated with an instance.

17. When would you want to use FSR (Fast Snapshot Restore)?
    FSR is useful when you need to reduce data access latency during data restoration from snapshots. It's beneficial for use cases like virtual desktop infrastructure (VDI), backup and restore test/dev volume copies, and booting from custom Amazon Machine Images (AMIs).

18. How can you change the default root EBS size in CloudFormation?
    You can change the default root EBS size in CloudFormation by using the BlockDeviceMappings property in your CloudFormation template.

19. How can you transfer data from an EBS volume to an S3 bucket?
    You can use the AWS S3 sync command to transfer data from an EBS volume to an S3 bucket.

20. How can you change the default root EBS size in CloudFormation?
    To change the default root EBS size in CloudFormation, you can use the BlockDeviceMappings property in your CloudFormation template and specify the desired EBS volume configuration.

21. How to Set Up Amazon EBS?
    Setting up Amazon EBS involves creating an EBS volume, storing EBS volume data from a snapshot, attaching the EBS volume to an EC2 instance, and detaching the volume when necessary.

22. How to Copy files from one EBS to Another EBS?
    To copy files from one EBS to another, you need to attach both EBS volumes to an instance, copy the files between them, and then unmount and detach the volumes.

23. What is EBS Block Express, and how does it work?
    EBS Block Express is the next version of Amazon EBS storage architecture designed for high-performance block storage with sub-millisecond latency. It communicates with EC2 instances using Scalable Reliable Datagrams (SRD) and offers modular software and hardware for improved performance and features.

24. What are the advantages of using Amazon EBS?
    The advantages of using Amazon EBS include reliable and secure storage, secure access control, higher performance with SSD technology, and easy data backup through snapshots.

25. What is Elastic Block Store, and how does it work?
    Amazon Elastic Block Store (EBS) is a high-performance, easy-to-use block storage service designed for use with Amazon EC2 instances. It provides block-level storage volumes for AWS EC2 instances and utilizes SSD technology for high throughput and low-latency performance.

26. How can I change an existing EBS volume's capacity, performance, or type? You can change an existing EBS volume's configuration, including capacity, performance, or type, using Elastic Volumes, which allows for adjustments through CLI, API, or the AWS Management Console.

27. What is the Amazon Web Services (AWS) Key Management Service (KMS)? AWS Key Management Service (KMS) is a managed service that enables the creation and management of encryption keys used for data encryption. It works with various AWS services to provide data encryption with user-controlled keys and offers logs of key usage for compliance purposes.

28. How to change an existing EBS volume's capacity, performance, or type?
    You can easily modify an existing EBS volume's configuration by using Elastic Volumes. This allows you to adjust the capacity, performance, or volume type through a simple CLI call, API call, or by making changes in the AWS Management Console.

29. What is the Amazon Web Services (AWS) Key Management Service (KMS)? AWS Key Management Service (KMS) is a managed service that simplifies the creation and management of encryption keys used for data encryption in AWS. It integrates with various AWS services like Amazon EBS, Amazon S3, and Amazon Redshift to enable you to encrypt your data with keys you control. AWS KMS also provides logs of key usage, aiding in meeting regulatory and compliance requirements.

These are the explanations for the AWS EBS interview questions and answers. If you have any more questions or need further information, feel free to ask.