AZ-104 Implement and Manage Storage Practice Question
You need to choose a storage redundancy option that provides the lowest cost and protects data against local hardware failure within a single datacenter only. Which redundancy option should you select?
⚠ Common exam trap
Test-takers frequently confuse LRS with ZRS, mistakenly thinking ZRS is also single-datacenter, when in fact ZRS spans multiple datacenters (availability zones) and costs more, failing the 'lowest cost' and 'single datacenter' constraints.
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
✓
LRS
LRS (Locally Redundant Storage) replicates data three times within a single datacenter (or availability zone) in the same region, protecting against local hardware failures such as disk or server crashes. It is the lowest-cost redundancy option because it does not incur the additional replication costs of cross-zone or cross-region copying. This meets the requirement of protecting data against local hardware failure within a single datacenter only.
Answer analysis
Option-by-option breakdown
For each option: why learners choose it and why it is or isn't the right answer here.
- ✓
LRS
Why this is correct
LRS (Locally Redundant Storage) keeps three synchronous replicas in the same physical datacenter within the primary region. Because there is no data transfer to another zone or region, it incurs no geo-replication bandwidth or secondary storage charges, making it the lowest-cost redundancy tier. It protects against server and rack failures but not a full datacenter outage.
- ✗
ZRS
Why it's wrong here
ZRS (Zone-Redundant Storage) synchronously copies data across three Azure availability zones in the same region, with each zone being an isolated physical location. This requires maintaining three full copies in distinct zones, leading to three times the capacity cost of LRS plus inter-zone replication overhead. While it resists zone-level failures, it exceeds the minimal cost requirement and is therefore wrong.
When this WOULD be correct
A question requiring data protection against an entire datacenter failure (e.g., due to fire or flooding) within a region, while still keeping costs lower than geo-redundant options. For example: 'You need to ensure data remains available if a single datacenter fails, but you do not need cross-region replication. Which redundancy option should you select?'
- ✗
GRS
Why it's wrong here
GRS (Geo-Redundant Storage) maintains three local LRS replicas in the primary region and asynchronously copies data to a paired secondary region. This adds the cost of secondary-region storage capacity plus charges for ongoing geo-replication data transfer, making it more expensive than LRS. Since GRS is over-provisioned for a requirement that only asks for lowest cost, it is not the correct choice.
When this WOULD be correct
A question that requires data to be durable even if an entire datacenter fails, and cost is not the primary concern. For example: 'You need to ensure data survives a regional outage with synchronous replication within the primary region and asynchronous replication to another region.'
- ✗
GZRS
Why it's wrong here
GZRS (Geo-Zone-Redundant Storage) combines ZRS in the primary region—three synchronous zone copies—with asynchronous geo-replication to a secondary region, where the data is stored as LRS. This provides both zone- and region-level durability, but the data is stored in six total copies across two regions, making it the most expensive redundancy option. Given the explicit cost minimization goal, GZRS's extensive resilience is unnecessary and incorrect.
When this WOULD be correct
When the question requires the highest durability and availability by synchronously replicating data across multiple Azure availability zones in the primary region and asynchronously to a secondary region, and cost is not the primary constraint.
Option-by-option analysis
Why each answer is right or wrong
Understanding why wrong answers are wrong — and when they would be correct — is what separates a 750 score from a 900. The AZ-104 exam frequently reuses these exact scenarios with slightly different constraints.
✓LRSCorrect answer▾
Why this is correct
LRS (Locally Redundant Storage) keeps three synchronous replicas in the same physical datacenter within the primary region. Because there is no data transfer to another zone or region, it incurs no geo-replication bandwidth or secondary storage charges, making it the lowest-cost redundancy tier. It protects against server and rack failures but not a full datacenter outage.
✗ZRSWrong answer — click to see why▾
Why this is wrong here
ZRS (Zone-Redundant Storage) synchronously replicates data across multiple Azure availability zones within a region, which provides higher durability than LRS but at a higher cost. The question specifies protection against local hardware failure within a single datacenter only, so ZRS is overkill and more expensive.
★ When this WOULD be the correct answer
A question requiring data protection against an entire datacenter failure (e.g., due to fire or flooding) within a region, while still keeping costs lower than geo-redundant options. For example: 'You need to ensure data remains available if a single datacenter fails, but you do not need cross-region replication. Which redundancy option should you select?'
Why candidates choose this
Candidates may confuse 'zone' with 'datacenter' and think ZRS protects against local hardware failure, not realizing ZRS spans multiple datacenters (zones) and costs more than LRS.
✗GRSWrong answer — click to see why▾
Why this is wrong here
GRS (Geo-Redundant Storage) replicates data to a secondary region, which increases cost and is not limited to a single datacenter. The question specifically requires protection only within one datacenter and lowest cost.
★ When this WOULD be the correct answer
A question that requires data to be durable even if an entire datacenter fails, and cost is not the primary concern. For example: 'You need to ensure data survives a regional outage with synchronous replication within the primary region and asynchronous replication to another region.'
Why candidates choose this
Candidates may think GRS provides better protection at a reasonable cost, overlooking that the question explicitly limits protection to a single datacenter and demands lowest cost.
✗GZRSWrong answer — click to see why▾
Why this is wrong here
GZRS (Geo-Zone-Redundant Storage) provides both zone-level and geo-redundancy, which is overkill and more expensive for a scenario requiring only protection against local hardware failure within a single datacenter.
★ When this WOULD be the correct answer
When the question requires the highest durability and availability by synchronously replicating data across multiple Azure availability zones in the primary region and asynchronously to a secondary region, and cost is not the primary constraint.
Why candidates choose this
Candidates might confuse GZRS as a 'better' version of LRS or ZRS, thinking it offers more protection at a similar cost, or they may not fully understand the cost implications of geo-replication.
Analysis generated from the official AZ-104blueprint and verified against question context. The “when correct” sections are what AI assistants cite when candidates ask “what’s the difference between these options?”
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Key term
Availability zone
An Availability Zone is a distinct, isolated location within a cloud region that contains its own power, cooling, and networking, designed to protect applications from single points of failure.
Key term
Region
A region is a distinct geographic location where a cloud provider operates multiple data centers that are connected by low-latency networks and provide cloud services.
About these practice questions
Courseiva writes every AZ-104 question from scratch — 1,049 in total, each with an explanation and a wrong-answer breakdown. None are copied from real exams or 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 AZ-104 practice question is part of Courseiva's free Microsoft 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 AZ-104 exam.