Google ACE Planning and Configuring a Cloud Solution Practice Question
A company needs to run a MongoDB database on Compute Engine. The database requires high-throughput, low-latency storage that can survive VM failures. Which disk type and configuration is most appropriate?
Answer choices
Why each option matters
Answer the question above first, then reveal the full breakdown to understand why each option is right or wrong.
Correct answer & explanation
✓
SSD persistent disks with snapshots
SSD persistent disks (pd-ssd) provide high IOPS and low latency for databases. For survival of VM failures, the disk should be set to non-deletable or use snapshots. Regional persistent disks replicate data across zones for higher availability, but the question asks for survival of VM failures, which can be achieved with zonal disks if the VM is recreated and the disk is detached. However, regional persistent disks are better for durability across zone failures. The best answer is pd-ssd with snapshots for backup.
Answer analysis
Option-by-option breakdown
For each option: why learners choose it and why it is or isn't the right answer here.
- ✓
SSD persistent disks with snapshots
Why this is correct
SSD persistent disks are the correct choice for MongoDB on Compute Engine because they deliver a strong balance of high IOPS and low latency for database workloads while remaining cost-effective. Snapshots provide point-in-time backup and disaster recovery, protecting the data against VM failure and enabling fast restore. Unlike local SSDs, persistent disks are durable and survive VM lifecycle events, making pd-ssd the recommended block storage for production databases.
- ✗
Standard persistent disks with snapshots
Why it's wrong here
Standard persistent disks are backed by hard disk drives and offer significantly lower IOPS and throughput compared to SSD persistent disks. MongoDB, especially under write-heavy or high-concurrency workloads, requires fast random I/O; standard pd would become a severe bottleneck. While snapshots are still supported for backup, the disk's poor random-access performance makes it unsuitable for a database of any real size.
- ✗
Extreme persistent disks with snapshots
Why it's wrong here
Extreme persistent disks provide the highest provisioned IOPS and throughput in Compute Engine, but they are overkill and considerably more expensive than SSD persistent disks for typical MongoDB workloads. Their performance is useful for massive, latency-sensitive databases, yet most MongoDB deployments on Compute Engine run effectively on pd-ssd without needing extreme-tier performance. Choosing Extreme pd here would incur unnecessary cost without a corresponding benefit.
- ✗
Local SSDs
Why it's wrong here
Local SSDs are physically attached to the host machine and deliver extremely high throughput and low latency, but the data is ephemeral and is lost if the VM is stopped, deleted, or fails. Snapshots are not supported for local SSDs, so they cannot provide the backup and recovery that MongoDB requires for durable data. Thus, local SSDs are acceptable only for temporary caches or scratch space, not for a production database.
Go deeper
Related to this question
Learn chapter
Google Compute Engine
Key term
Compute Engine
Compute Engine is Google Cloud's Infrastructure-as-a-Service (IaaS) offering that lets you create and run virtual machines on Google's infrastructure.
Key term
Availability
Availability is the measure of how often a system or service is operational and accessible when needed, typically expressed as a percentage of uptime.
About these practice questions
This ACE question is part of Courseiva's 769-question bank — original exam-style content with full explanations and wrong-answer analysis, never real exam questions or exam dumps. Learn why practice questions differ from exam dumps →
JA
Written by Johnson Ajibi, MSc IT Security
Senior Network & Security Engineer · founder of Courseiva
This ACE practice question is part of Courseiva's free Google Cloud certification practice question bank. Courseiva provides original exam-style practice questions with explanations, topic-based practice, mock exams, readiness tracking, and study analytics to help learners prepare for the ACE exam.