AWS storage services (for example, Amazon S3, Amazon EFS)

Can you describe what Amazon S3 is and when you would use it over Amazon EFS?

Amazon S3 is an object storage service that offers industry-leading scalability, data availability, security, and performance. It is typically used for storing and retrieving any amount of data, such as websites, mobile applications, backup and restore, archive, enterprise applications, IoT devices, and big data analytics. You would use Amazon S3 over Amazon EFS when you need a highly durable, scalable, and secure object storage solution that isn’t limited by file system structure or size and when you require features such as versioning and lifecycle policies.

How does Amazon EFS differ from Amazon EBS?

Amazon Elastic File System (EFS) is a scalable file storage service for use with AWS Cloud services and on-premises resources. It’s easy to use and offers a simple interface that allows you to create and configure file systems quickly. Amazon Elastic Block Store (EBS) provides block-level storage volumes for use with EC2 instances. EFS is used when you need a file storage system that can be shared across different EC2 instances, while EBS is used when you need persistent block-level storage for a single EC2 instance.

What is the significance of S3 storage classes and when would you recommend using S3 Intelligent-Tiering?

S3 storage classes are designed to cater to different use cases by offering various levels of accessibility, durability, and cost. S3 Intelligent-Tiering is recommended when you have data with unknown or changing access patterns, as it automatically moves data to the most cost-effective storage tier without performance impact or retrieval fees.

What mechanisms does Amazon S3 provide to secure data at rest?

Amazon S3 provides several mechanisms to secure data at rest, including server-side encryption with Amazon S3-managed keys (SSE-S3), AWS Key Management Service (AWS KMS) keys (SSE-KMS), or customer-provided keys (SSE-C). Additionally, S3 supports default encryption on buckets to ensure all new objects are encrypted.

How does Amazon EFS’s performance mode and throughput mode affect file system operations, and when would you choose one over the other?

Amazon EFS offers two performance modes: General Purpose, which is suitable for most file systems and provides a balance between latency and throughput, and Max I/O, which is optimized for high levels of aggregate throughput and operations per second at the cost of slightly higher latencies. You should choose Max I/O when your workload requires high levels of throughput. EFS also provides two throughput modes: Bursting Throughput and Provisioned Throughput. Bursting Throughput scales with the size of the file system, while Provisioned Throughput can be configured for applications that need a higher level of sustained throughput beyond what Bursting Throughput provides.

What is the primary difference between Amazon S3 and Amazon Glacier, and how would you determine which service to use for data storage?

The primary difference between Amazon S3 and Amazon Glacier is related to data access time and cost. Amazon S3 is designed for frequent data access with low latency, while Amazon Glacier is a low-cost storage option for data archiving, with retrieval times ranging from minutes to hours. You would determine which service to use based on the required access patterns—use Amazon S3 for active data and Amazon Glacier for long-term data archiving where access times can be flexible.

Can you explain the concept of S3 Lifecycle policies and how they help manage costs?

S3 Lifecycle policies help manage costs by automatically migrating objects to more cost-effective storage classes or by purging objects that are no longer needed. For example, you can create rules to move objects to S3 Standard-IA for infrequent access after a certain period or archive objects to Amazon Glacier after a set time. Lifecycle policies are also used to automatically delete expired objects or incomplete multipart uploads.

What is Amazon S3 Versioning, and what are the benefits of using it?

Amazon S3 Versioning is a feature that keeps multiple versions of an object within the same bucket. This means that you can easily recover from both unintended user actions and application failures. Benefits include easy recovery of data, protection against accidental overwrites and deletions, and the ability to retain a full history of changes.

How can you improve data transfer performance when uploading large amounts of data to Amazon S3?

To improve data transfer performance, you can use Amazon S3 Transfer Acceleration for faster uploads over long distances, enable multipart uploads to break down large files into smaller chunks and upload them in parallel, and leverage Amazon S3’s parallel requests capability to increase throughput.

How would you ensure high availability and durability of data using Amazon EFS?

Amazon EFS is designed to be highly available and durable, automatically replicating data across multiple Availability Zones within an AWS Region to prevent data loss due to failures. To further ensure high availability, you should deploy AWS resources that interact with EFS across multiple Availability Zones. For instance, setting up instances that mount the EFS file system in different Availability Zones can provide continued access to data in case one zone becomes unavailable.

In what scenarios would you consider using Amazon S3’s Cross-Region Replication (CRR)?

You would consider using Amazon S3’s Cross-Region Replication in scenarios where you need to comply with data residency requirements, want to replicate data for disaster recovery purposes, or want to maintain lower-latency access for users in different geographic locations.

What is the difference between Amazon S3’s “Standard” and “Reduced Redundancy Storage (RRS)” storage classes, and is RRS recommended for critical data?

The “Standard” storage class in Amazon S3 is designed to provide 999999999% (11 9’s) of durability and is suitable for critical data with high availability needs. Reduced Redundancy Storage (RRS) was an older offering that provided less durability at a lower cost, and was suitable for non-critical or reproducible data. However, RRS is no longer recommended for any data, and AWS has phased it out in favor of other more cost-effective and durable storage classes like S3 Standard-IA and S3 One Zone-IA.