Validation Quiz - MODULE 4
This 30-question quiz allows you to validate your knowledge of Amazon EBS before moving on to the practical lab.
Question 1
What does EBS stand for in Amazon EBS?
A) Elastic Block Storage
B) Elastic Block Store
C) Enterprise Backup Service
D) Extended Block System
See the answer
Answer: B
EBS stands for Elastic Block Store. It is a high-performance block storage service designed to be used with Amazon EC2. EBS volumes persist independently of the instance lifecycle and can be detached and reattached to another instance.
Question 2
What is the main difference between EBS and Instance Store?
A) EBS is faster
B) EBS is persistent, Instance Store is ephemeral
C) Instance Store is cheaper
D) No difference
See the answer
Answer: B
EBS is persistent storage: data survives the instance stop. Instance Store is ephemeral: data is lost when the instance is stopped or terminated. Instance Store offers better I/O performance but without persistence.
Question 3
Can an EBS volume be attached to multiple EC2 instances simultaneously?
A) Yes, always
B) No, never
C) Yes, but only with EBS Multi-Attach on certain types (io1/io2)
D) Only for gp3 volumes
See the answer
Answer: C
By default, an EBS volume can only be attached to one instance. However, EBS Multi-Attach allows an io1 or io2 volume to be attached to multiple EC2 Nitro instances in the same AZ. This requires a clustered file system.
Question 4
Does an EBS volume need to be in the same availability zone as the instance?
A) No, it can be in any AZ
B) Yes, it must be in the same AZ
C) No, it can be in another region
D) Only for gp2 volumes
See the answer
Answer: B
An EBS volume must be in the same availability zone as the EC2 instance to which it is attached. To use a volume in another AZ, you need to create a snapshot and then restore it in the new AZ.
Question 5
Which type of EBS volume offers the best price/performance ratio for most workloads?
A) gp2
B) gp3
C) io2
D) st1
See the answer
Answer: B
gp3 (General Purpose SSD) offers the best price/performance ratio. It is 20% cheaper than gp2 with higher baseline performance (3000 IOPS, 125 MB/s). IOPS and throughput can be increased independently of volume size.
Question 6
What is the difference between gp2 and gp3?
A) gp3 is older
B) gp2 ties IOPS to volume size, gp3 allows them to be configured independently
C) gp3 does not support encryption
D) No difference
See the answer
Answer: B
With gp2, IOPS are tied to volume size (3 IOPS/GB). With gp3, you can configure IOPS and throughput independently of size. gp3 offers 3000 IOPS baseline for free compared to 100 IOPS minimum for gp2.
Question 7
Which type of EBS volume is optimized for high-performance critical databases?
A) gp2
B) st1
C) io2 Block Express
D) sc1
See the answer
Answer: C
io2 Block Express is designed for critical workloads requiring sub-millisecond latency and up to 256,000 IOPS. It is ideal for transactional databases like Oracle, SQL Server, and SAP applications.
Question 8
Which type of EBS volume is the cheapest and suitable for infrequently accessed archives?
A) gp3
B) io1
C) st1
D) sc1 (Cold HDD)
See the answer
Answer: D
sc1 (Cold HDD) is the cheapest volume type. It is designed for infrequently accessed data where cost is paramount. It offers up to 250 IOPS and 250 MB/s. Ideal for archives and cold data.
Question 9
Can st1 and sc1 volumes be used as boot volumes?
A) Yes, both
B) No, neither
C) Only st1
D) Only sc1
See the answer
Answer: B
HDD volumes (st1 and sc1) cannot be used as boot volumes. Only SSD volumes (gp2, gp3, io1, io2) can serve as root volumes to boot an EC2 instance.
Question 10
What is an EBS snapshot?
A) A full copy of the volume stored in S3
B) A log of changes
C) A performance metric
D) A type of volume
See the answer
Answer: A
An EBS snapshot is a point-in-time backup of an EBS volume stored in Amazon S3. Snapshots are incremental: only the blocks changed since the last snapshot are saved, optimizing storage and costs.
Question 11
Are EBS snapshots incremental or full?
A) Always full
B) Incremental after the first snapshot
C) User's choice
D) Full for SSD volumes, incremental for HDD
See the answer
Answer: B
Snapshots are incremental. The first snapshot copies the entire volume. Subsequent snapshots only copy blocks changed since the previous snapshot. However, each snapshot contains all the information needed to restore the full volume.
Question 12
Can a snapshot be used to create a volume in another region?
A) No, snapshots are regional and cannot be copied
B) Yes, by first copying the snapshot to the other region
C) Yes, directly without copying
D) Only for io2 volume snapshots
See the answer
Answer: B
Snapshots are regional by default. To create a volume in another region, you must first copy the snapshot to that region with "Copy snapshot," then create the volume from the copy. This is useful for multi-region disaster recovery.
Question 13
Can you take a snapshot of an EBS volume while it is attached and in use?
A) No, the volume must be detached
B) Yes, but it is not recommended for databases without preparation
C) No, the instance must be stopped
D) Only for gp3 volumes
See the answer
Answer: B
You can take a snapshot of an attached and in-use volume. However, to ensure data consistency (especially for databases), it is recommended to: flush caches, freeze the file system, or stop the application during the snapshot capture.
Question 14
How to ensure EBS volumes are encrypted by default in an AWS account?
A) It is not possible
B) Enable "EBS encryption by default" in EC2 settings
C) Use only io2 volumes
D) Manually encrypt each volume
See the answer
Answer: B
In the EC2 settings of the AWS console, you can enable "EBS encryption by default." Once enabled, all new EBS volumes and snapshots will be automatically encrypted with the default KMS key or a custom key.
Question 15
Which AWS service is used to manage EBS encryption keys?
A) AWS IAM
B) AWS KMS (Key Management Service)
C) AWS Secrets Manager
D) AWS Certificate Manager
See the answer
Answer: B
AWS KMS (Key Management Service) manages encryption keys for EBS. You can use AWS's default KMS key or create your own CMKs (Customer Master Keys). EBS encryption uses AES-256.
Question 16
Which AWS CLI command creates a snapshot of an EBS volume?
A) aws ebs create-snapshot
B) aws ec2 create-snapshot --volume-id vol-xxx
C) aws s3 snapshot
D) aws ec2 backup-volume
See the answer
Answer: B
The command is aws ec2 create-snapshot --volume-id vol-xxx. You can add --description to document the snapshot. EBS is managed via EC2 commands, not a separate service in the API.
Question 17
How to increase the size of an EBS volume attached to a running instance?
A) Impossible, you must recreate the volume
B) Modify the volume, then extend the file system in the OS
C) Stop the instance necessarily
D) Detach and then reattach the volume
See the answer
Answer: B
You can modify the size of an EBS volume on the fly via "Modify Volume" in the console or CLI. After modification, you need to extend the file system in the OS (resize2fs for ext4, xfs_growfs for XFS) to use the additional space.
Question 18
Can you reduce the size of an EBS volume?
A) Yes, with the "Shrink Volume" function
B) No, you can only increase the size
C) Yes, but only if the volume is empty
D) Only for gp2 volumes
See the answer
Answer: B
It is impossible to reduce the size of an EBS volume directly. To have a smaller volume, you must: create a snapshot, create a new smaller volume, copy the data, then delete the old volume.
Question 19
What is the "burst balance" for a gp2 volume?
A) The billing balance
B) Accumulated IOPS credits allowing temporary performance bursts
C) Load balancing
D) The snapshot quota
See the answer
Answer: B
gp2 volumes under 1 TB accumulate IOPS credits when usage is below the baseline level. These credits allow "bursting" up to 3000 IOPS temporarily. The burst balance depletes if high IOPS are maintained for too long.
Question 20
Which CloudWatch metric to monitor to avoid performance issues on a gp2 volume?
A) VolumeReadOps
B) BurstBalance
C) VolumeQueueLength
D) All three
See the answer
Answer: D
All three metrics are important: BurstBalance indicates remaining IOPS credits (critical for gp2 < 1TB), VolumeQueueLength shows pending operations (high value = bottleneck), VolumeReadOps/WriteOps show I/O activity.
Question 21
What is "Delete on Termination" for an EBS volume?
A) Option that automatically deletes the volume when the instance is terminated
B) Option that deletes the volume after 30 days
C) Option that prevents deletion
D) Automatic backup option
See the answer
Answer: A
"Delete on Termination" is an attribute that, if enabled, automatically deletes the EBS volume when the associated EC2 instance is terminated. By default, it is enabled for the root volume and disabled for additional volumes.
Question 22
How to preserve a root volume when terminating an instance?
A) It is not possible
B) Disable "Delete on Termination" for this volume
C) Use an io2 volume
D) Create a snapshot before termination only
See the answer
Answer: B
To preserve the root volume, disable "Delete on Termination" before terminating the instance. This can be done during launch or via the console/CLI after launch (Modify instance attribute > Block device mapping).
Question 23
What is the advantage of io2 Block Express volumes over standard io2?
A) Lower price
B) Higher IOPS and throughput (up to 256K IOPS, 4000 MB/s)
C) Available in more regions
D) No difference
See the answer
Answer: B
io2 Block Express offers superior performance: up to 256,000 IOPS (vs 64,000 for io2), up to 4,000 MB/s throughput, sub-millisecond latency, and volumes up to 64 TB. It requires EC2 Nitro instances.
Question 24
How to attach an EBS volume to an EC2 instance with AWS CLI?
A) aws ebs attach-volume
B) aws ec2 attach-volume --volume-id vol-xxx --instance-id i-xxx --device /dev/sdf
C) aws ec2 mount-volume
D) aws ec2 connect-volume
See the answer
Answer: B
The command is aws ec2 attach-volume --volume-id vol-xxx --instance-id i-xxx --device /dev/sdf. The --device parameter specifies the device name in the instance. After attachment, you need to mount the volume in the OS.
Question 25
After attaching a new EBS volume, what step is necessary in Linux?
A) Nothing, the volume is automatically available
B) Format the volume (mkfs) and mount it (mount)
C) Restart the instance
D) Modify the Security Group
See the answer
Answer: B
For a new volume: 1) Identify the device (lsblk), 2) Create a file system if new (mkfs -t ext4 /dev/xvdf), 3) Create a mount point (mkdir /data), 4) Mount the volume (mount /dev/xvdf /data), 5) Add to /etc/fstab for automatic mounting.
Question 26
How to make the mounting of an EBS volume persistent after a reboot?
A) Use an io2 volume
B) Add an entry in /etc/fstab
C) Enable "Auto Mount" in the AWS console
D) It is not possible
See the answer
Answer: B
To make the mount persist after a reboot, add a line in /etc/fstab. Use the volume's UUID (obtained with blkid) rather than the device name which can change. Example: UUID=xxx /data ext4 defaults,nofail 0 2
Question 27
Which fstab option is recommended to avoid boot failures if an EBS volume is unavailable?
A) defaults
B) nofail
C) auto
D) rw
See the answer
Answer: B
The "nofail" option allows the instance to boot even if the volume cannot be mounted. Without this option, a missing or problematic volume can block the instance startup. It's a best practice for data volumes.
Question 28
What is Amazon Data Lifecycle Manager (DLM) for EBS?
A) A data migration service
B) A service that automates the creation, retention, and deletion of snapshots
C) A monitoring tool
D) An encryption service
See the answer
Answer: B
Amazon DLM automates the lifecycle management of EBS snapshots. You define policies that specify: which volumes to back up (via tags), snapshot frequency, retention, and cross-region replication. This simplifies backups and compliance.
Question 29
An EBS volume shows lower than expected IOPS. What is the first check?
A) Does the EC2 instance type support provisioned IOPS?
B) Is encryption enabled?
C) Is the region correct?
D) Is the snapshot complete?
See the answer
Answer: A
EC2 instances have EBS bandwidth limits. A too-small instance cannot utilize all the IOPS of a high-performance volume. Check that the instance type is "EBS-optimized" and that its EBS limits exceed the volume's IOPS.
Question 30
What is the best practice for database backups on EBS?
A) Take snapshots during peak hours
B) Stop the DB, flush data, then take the snapshot
C) Never take snapshots
D) Use only gp2 volumes
See the answer
Answer: B
To ensure data consistency, the best practice is: 1) Stop writes or put the DB in backup mode, 2) Flush caches to disk, 3) Take the snapshot, 4) Resume normal operations. Some DBs have built-in tools for this.
Result
Count your correct answers:
- 27-30: Excellent - You master EBS storage
- 22-26: Good - A few points to review
- 17-21: Average - Review the course before the lab
- Less than 17: Insufficient - Retake the course from the beginning
Proceed to the Storage Lab once you have achieved at least 22 correct answers.