AWS Elastic File System (EFS) Interview Guide: Top 10 Questions Explained
As an experienced professional cloud developer, I understand that you want me to provide the top 10 AWS EFS (Elastic File System) interview questions and answers. Here they are:
- Q: What is AWS EFS, and how does it differ from other AWS storage services?
A: AWS EFS (Elastic File System) is a fully managed, elastic, and scalable file storage service that can be mounted on multiple EC2 instances or other AWS resources simultaneously. It’s designed for high availability and durability, and it supports the Network File System (NFS) protocol. Unlike EBS (Elastic Block Store) and S3 (Simple Storage Service), EFS provides shared access to files for multiple resources, making it ideal for applications that require a shared file system.
- Q: How does AWS EFS ensure high availability and durability?
A: AWS EFS stores each file across multiple Availability Zones (AZs) within a region, ensuring high availability and durability. This distributed storage model helps protect data from single-AZ failures and provides consistent low-latency access to data from multiple resources.
- Q: What are the performance modes of AWS EFS?
A: AWS EFS provides two performance modes: General Purpose and Max I/O. General Purpose is the default mode, designed for most applications, offering low latency and high throughput. Max I/O is suitable for applications that require higher levels of throughput, at the cost of slightly increased latency.
- Q: How does AWS EFS handle throughput and IOPS?
A: EFS automatically scales the throughput and IOPS (Input/Output Operations Per Second) based on the amount of data stored. Throughput scales linearly as the file system grows, with an additional burst credit system that allows for temporary increases in throughput for short periods.
- Q: How can you mount an EFS file system on an EC2 instance?
A: To mount an EFS file system on an EC2 instance, you need to install the NFS client on the instance, create a mount point, and then mount the EFS file system using the mount command with the appropriate NFS options.
- Q: Can you use EFS with AWS Lambda?
A: Yes, you can use EFS with AWS Lambda. By attaching an EFS file system to a Lambda function, the function can access and share files with other Lambda functions or resources, enabling use cases like machine learning, data processing, and content management.
- Q: What is AWS EFS Infrequent Access (EFS-IA)?
A: EFS-IA is a storage class that allows you to store infrequently accessed files at a lower cost compared to the standard EFS storage. You can use EFS Lifecycle policies to automatically transition files from the standard EFS storage to EFS-IA based on access patterns and age.
- Q: How do you secure data in AWS EFS?
A: You can secure data in AWS EFS by using AWS Identity and Access Management (IAM) policies to control access, Network ACLs (Access Control Lists) and Security Groups to restrict network traffic, and encrypting data at rest using AWS Key Management Service (KMS) keys.
- Q: How does AWS EFS handle backups and disaster recovery?
A: AWS EFS provides automatic backups through AWS Backup, allowing you to create, manage, and restore backups according to a defined schedule or on-demand. Additionally, you can use AWS DataSync to replicate your EFS file system across regions for disaster recovery purposes.
- Q: How is AWS EFS billed?
A: AWS EFS billing is based on the amount of storage used and the amount of data read or written to the file system. You are charged for standard EFS storage, EFS Infrequent Access (EFS-IA) storage, and any additional costs for backups, data transfer, and management features. EFS storage costs vary by region, and you can save on costs by leveraging EFS-IA for infrequently accessed files.