AWS Compute and Storage Services 4 — Questions and Answers
Question 1: A developer needs to share an EFS file system across multiple EC2 instances in different Availability Zones within the same VPC. What must be configured?
- One mount target per EFS file system in any single AZ
- Mount targets in each AZ where EC2 instances reside (Correct answer)
- An S3 VPC endpoint to route EFS traffic
- An EBS multi-attach volume instead of EFS
Correct answer: Mount targets in each AZ where EC2 instances reside
Amazon EFS requires a mount target in each Availability Zone where EC2 instances need access to the file system.
Question 2: Which EC2 instance type family is optimized for applications requiring high memory-to-vCPU ratios, such as in-memory databases?
- C-family (Compute Optimized)
- R-family (Memory Optimized) (Correct answer)
- I-family (Storage Optimized)
- T-family (Burstable)
Correct answer: R-family (Memory Optimized)
R-family EC2 instances are Memory Optimized and designed for workloads that process large datasets in memory, such as SAP HANA or Redis.
Question 3: What S3 feature automatically moves objects between storage classes based on defined lifecycle rules?
- S3 Replication
- S3 Intelligent-Tiering automatic transitions
- S3 Lifecycle policies with transition actions (Correct answer)
- S3 Transfer Acceleration
Correct answer: S3 Lifecycle policies with transition actions
S3 Lifecycle policies with transition actions automatically move objects to cheaper storage classes (e.g., Standard → IA → Glacier) based on age.
Question 4: An EC2 instance in a private subnet needs to download software updates from the internet. What is the correct solution?
- Assign an Elastic IP to the instance
- Place a NAT Gateway in a public subnet and update the private subnet route table (Correct answer)
- Use an Internet Gateway attached to the private subnet
- Enable DNS resolution on the VPC
Correct answer: Place a NAT Gateway in a public subnet and update the private subnet route table
A NAT Gateway placed in a public subnet allows instances in private subnets to initiate outbound internet traffic without being directly reachable from the internet.
Question 5: Which EBS volume type provides the highest throughput for large sequential workloads like data warehouses and log processing?
- gp3 (General Purpose SSD)
- io2 Block Express (Provisioned IOPS SSD)
- st1 (Throughput Optimized HDD) (Correct answer)
- sc1 (Cold HDD)
Correct answer: st1 (Throughput Optimized HDD)
st1 (Throughput Optimized HDD) is designed for large, sequential workloads and delivers up to 500 MB/s throughput at a lower cost than SSDs.
Question 6: What is the purpose of an EC2 instance's user data script?
- To define IAM permissions for the instance at runtime
- To run bootstrap commands automatically when the instance first starts (Correct answer)
- To configure the instance's security group rules dynamically
- To attach additional EBS volumes on demand
Correct answer: To run bootstrap commands automatically when the instance first starts
User data scripts are executed automatically during the first boot of an EC2 instance, commonly used to install software or configure settings.
Question 7: A company stores 100 TB of rarely accessed compliance data that must be retrievable within 12 hours. Which S3 storage class is the most cost-effective choice?
- S3 Standard
- S3 Glacier Flexible Retrieval (Correct answer)
- S3 Glacier Instant Retrieval
- S3 Standard-IA
Correct answer: S3 Glacier Flexible Retrieval
S3 Glacier Flexible Retrieval offers very low storage costs for archive data with retrieval times ranging from minutes to 12 hours, fitting the compliance scenario.
AWS Compute and Storage Services 4
A developer needs to share an EFS file system across multiple EC2 instances in different Availability Zones within the same VPC.
What must be configured?