Azure Storage Redundancy: ZRS, GZRS, RA-GZRS, and More
A media company stores project video assets in Azure Blob Storage. The business requires the data to survive a single availability zone outage in the primary region. In addition, if the primary region becomes unavailable, operations staff must still be able to read the most recently replicated copy from the secondary region right away, even if writes are temporarily unavailable. Which redundancy option best meets this requirement?
Quick Answer
The answer is RA-GZRS, or Read-Access Geo-Zone-Redundant Storage. This option meets both requirements because it combines zone-redundant storage (ZRS) within the primary region, ensuring data survives a single availability zone outage, with geo-redundant storage (GRS) that replicates data to a secondary region. The critical “RA” prefix enables immediate read access to the most recently replicated copy in the secondary region after a primary region failure, even when writes are temporarily unavailable. On the AZ-104 exam, this scenario tests your understanding of Azure Storage redundancy options for zone and geo disaster recovery, often appearing as a scenario where you must distinguish between GZRS and RA-GZRS. A common trap is choosing GZRS alone, which does not allow read access until Microsoft initiates a failover. Remember the mnemonic: “RA-GZRS = Read Always after Geo-Zone failure,” emphasizing that the read-access feature is what makes it the right choice for immediate operational continuity.
⚠ Common exam trap
A common mix-up: candidates confuse GZRS with RA-GZRS, forgetting that GZRS alone does not provide read access to the secondary region; the 'RA' prefix is required for immediate read access during a primary region outage.
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
✓
RA-GZRS
RA-GZRS (Read-Access Geo-Zone-Redundant Storage) is correct because it combines zone-redundant storage (ZRS) within the primary region to survive a single availability zone outage, and geo-redundant storage (GRS) to replicate data to a secondary region. The 'RA' prefix enables read access to the secondary region immediately after a primary region failure, allowing operations staff to read the most recently replicated copy even if writes are temporarily unavailable.
Answer analysis
Option-by-option breakdown
For each option: why learners choose it and why it is or isn't the right answer here.
- ✗
ZRS
Why it's wrong here
Zone-redundant storage survives a zone failure, but it does not provide a readable secondary region.
When this WOULD be correct
A question requiring data to survive an availability zone outage within a single region, with no need for cross-region disaster recovery or read access from a secondary region. For example: 'An application needs high availability within a single region and must tolerate an availability zone failure. Which redundancy option should be used?'
- ✗
GZRS
Why it's wrong here
Geo-zone-redundant storage adds geo-replication, but the secondary region is not directly readable.
When this WOULD be correct
A company requires data to be durable across regions and can tolerate a brief delay in accessing the secondary copy after a primary region failure. They do not need immediate read access to the secondary region; a manual failover process is acceptable.
- ✗
RA-GRS
Why it's wrong here
Read-access geo-redundant storage gives secondary read access, but it does not protect against zone failure in the primary region.
When this WOULD be correct
A company requires read access to a secondary region during a primary region outage, but data durability only needs to survive a region-level disaster, not a zone-level failure. For example, a backup storage solution where the primary region is a single data center and the secondary region provides read-only access during failover.
- ✓
RA-GZRS
Why this is correct
Read-access geo-zone-redundant storage combines zone resilience with geo-replication and secondary read access.
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.
✓RA-GZRSCorrect answer▾
Why this is correct
Read-access geo-zone-redundant storage combines zone resilience with geo-replication and secondary read access.
✗ZRSWrong answer — click to see why▾
Why this is wrong here
ZRS replicates data synchronously across three availability zones in a single region, but does not provide a secondary region for disaster recovery. The requirement for reading from a secondary region immediately after a primary region outage is not met.
★ When this WOULD be the correct answer
A question requiring data to survive an availability zone outage within a single region, with no need for cross-region disaster recovery or read access from a secondary region. For example: 'An application needs high availability within a single region and must tolerate an availability zone failure. Which redundancy option should be used?'
Why candidates choose this
Candidates may choose ZRS because it protects against zone failures, but they overlook the additional requirement for cross-region read access in the event of a primary region outage.
✗GZRSWrong answer — click to see why▾
Why this is wrong here
GZRS replicates data to a secondary region asynchronously, but it does not provide read access to the secondary region unless a failover is initiated. The requirement to read from the secondary region immediately after a primary region outage, without waiting for failover, necessitates RA-GZRS.
★ When this WOULD be the correct answer
A company requires data to be durable across regions and can tolerate a brief delay in accessing the secondary copy after a primary region failure. They do not need immediate read access to the secondary region; a manual failover process is acceptable.
Why candidates choose this
Candidates may confuse GZRS with RA-GZRS, thinking that GZRS also provides read-access geo-redundancy, or they may overlook the 'read-access' requirement in the question.
✗RA-GRSWrong answer — click to see why▾
Why this is wrong here
RA-GRS provides read-access to a secondary region during a primary region outage, but it does not guarantee data survival after a single availability zone outage in the primary region because GRS replicates across regions, not zones, and a zone failure could still cause data loss if the primary region has only one zone.
★ When this WOULD be the correct answer
A company requires read access to a secondary region during a primary region outage, but data durability only needs to survive a region-level disaster, not a zone-level failure. For example, a backup storage solution where the primary region is a single data center and the secondary region provides read-only access during failover.
Why candidates choose this
Candidates may confuse RA-GRS with RA-GZRS, thinking that read-access geo-redundant storage automatically includes zone-level redundancy, or they may overlook the requirement to survive an availability zone outage in the primary region.
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?”
Quick reference
Azure Blob Storage Tier Comparison
| Tier | Storage Cost | Retrieval Cost | Latency | Use Case |
|---|---|---|---|---|
| Hot | Highest | Lowest | Immediate | Active data, frequent reads |
| Cool | Lower | Higher | Immediate | Data accessed < once / month |
| Cold | Lower still | Higher | Immediate | Data accessed < once / quarter |
| Archive | Lowest | Highest + rehydration delay | Hours | Long-term compliance retention |
Go deeper
Related to this question
Learn chapter
Managed Identities for Azure Resources
Key term
GRS
GRS (Georedundant Storage) is a data replication method that copies your stored data to a secondary region hundreds of miles away to protect against regional disasters.
Key term
ZRS
ZRS (Zone Redundant Storage) is a data storage option in Microsoft Azure that automatically replicates your data across multiple physical locations within a single region to keep it safe even if an entire data center goes down.
About these practice questions
This AZ-104 question is part of Courseiva's 1,049-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 →
Same concept, more angles
5 more ways this is tested on AZ-104
These questions test the same concept from different angles. Work through them to make sure you can recognise it however the exam phrases it.
Variation 1. A company wants its file share data to be automatically copied to a paired Azure region, and administrators want to read the secondary copy during a disaster test. Which redundancy option should they use?
easy- A.ZRS
- B.LRS
- ✓ C.RA-GRS
- D.Cool
Why C: RA-GRS (Read-Access Geo-Redundant Storage) is correct because it replicates data to a paired secondary region asynchronously and provides read-only access to that secondary copy. This allows administrators to read the secondary copy during a disaster test without impacting the primary region. ZRS and LRS do not replicate to a paired region, and Cool is a tier, not a redundancy option.
Variation 2. An Azure Files share must stay available if one availability zone in its primary region fails. The business does not need replication to another region. Which redundancy option should you choose for the storage account?
easy- A.Locally redundant storage (LRS)
- ✓ B.Zone-redundant storage (ZRS)
- C.Geo-redundant storage (GRS)
- D.Read-access geo-redundant storage (RA-GRS)
Why B: Zone-redundant storage (ZRS) synchronously replicates your Azure Files share across three Azure availability zones within the primary region. This ensures the share remains available if one zone fails, without requiring replication to another region. LRS only replicates within a single data center, while GRS and RA-GRS involve secondary region replication, which the business does not need.
Variation 3. A workload must keep storage available if one availability zone in the primary region fails. Geo-failover is optional, but the account must still meet the zone-failure requirement. Which two redundancy options satisfy this? Select two.
medium- A.LRS
- ✓ B.ZRS
- C.GRS
- ✓ D.GZRS
- E.RA-GRS
Why B: Both ZRS and GZRS meet the zone-failure requirement. ZRS synchronously replicates data across three availability zones within a single region, ensuring availability if one zone fails. GZRS also replicates synchronously across availability zones in the primary region (combining ZRS with geo-redundancy), so it also satisfies the requirement even without considering the optional geo-failover. LRS, GRS, and RA-GRS do not provide zone-level redundancy within the primary region.
Variation 4. A team wants a storage option that stays available if one availability zone in the primary region fails. Which two redundancy options meet that requirement? Select two.
easy- ✓ A.Zone-redundant storage (ZRS).
- ✓ B.Geo-zone-redundant storage (GZRS).
- C.Locally redundant storage (LRS).
- D.Geo-redundant storage (GRS).
- E.Read-access geo-redundant storage (RA-GRS).
Why A: Zone-redundant storage (ZRS) synchronously replicates data across three Azure availability zones within the primary region. If one zone fails, the data remains accessible from the other zones, ensuring high availability without requiring failover to a secondary region.
Variation 5. You need a storage redundancy option that keeps data available if an entire availability zone in the primary region fails, but you do not need cross-region replication. Which redundancy option should you choose?
medium- A.LRS
- ✓ B.ZRS
- C.GRS
- D.RA-GRS
Why B: B is correct because Zone-Redundant Storage (ZRS) synchronously replicates data across three Azure availability zones within a single region, ensuring data remains available if an entire zone fails. This meets the requirement of no cross-region replication while providing zone-level fault tolerance.
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.