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Technical Lab: Configure Azure Storage redundancy

Questions​

Question 1 — Multiple Choice​

An operations team needs to ensure that data from a storage account remains available even if an entire Azure region becomes unavailable, without depending on manual failover. Which redundancy option meets this requirement?

A) Zone-Redundant Storage (ZRS)

B) Geo-Redundant Storage (GRS)

C) Geo-Zone-Redundant Storage (GZRS)

D) Locally Redundant Storage (LRS)

Question 2 — Technical Scenario​

An administrator configured a storage account with Read-Access Geo-Redundant Storage (RA-GRS). During a test, they attempt to read data directly from the secondary endpoint using the following URL:

https://myaccount-secondary.blob.core.windows.net/container/file.txt

The read works under normal conditions. However, after a failover initiated by the administrator via the Azure portal, the team notices that the secondary endpoint stopped responding. What is the most likely cause of this behavior?

A) The failover converts the account to LRS, eliminating secondary replication.

B) After the failover, the secondary region becomes the new primary and the -secondary suffix ceases to exist until a new secondary region is provisioned.

C) The secondary endpoint is permanently disabled after any failover, requiring account recreation.

D) RA-GRS is downgraded to GRS after failover, blocking reads on the secondary for 30 days.

Question 3 — True or False​

Zone-Redundant Storage (ZRS) protects data against the total unavailability of an Azure region, as it replicates the three data copies across availability zones distributed geographically in different regions.

Question 4 — Technical Scenario​

A company operates in a single Azure region and needs a storage account that tolerates the complete failure of a physical datacenter within that region, but has no geographic recovery requirements. Cost should be as low as possible within these constraints. Consider the table below:

OptionCopiesProtection scopeRelative cost
LRS3Single datacenterLowest
ZRS3Zones in same regionMedium
GRS6Two regionsHigh
GZRS6Zones + two regionsHighest

Which option should be chosen?

A) LRS, as it maintains three copies in the same datacenter at minimum cost.

B) GRS, as it guarantees protection against datacenter failure through geographic replication.

C) ZRS, as it distributes copies across availability zones within the same region, protecting against datacenter failure.

D) GZRS, as it offers the highest level of protection available at the lowest relative cost.

Question 5 — Multiple Choice​

An administrator needs to change the redundancy of an existing storage account from LRS to GRS using Azure CLI. Which command represents the correct approach?

A)

az storage account update \
  --name myaccount \
  --resource-group my-rg \
  --sku Standard_GRS

B)

az storage account create \
  --name myaccount \
  --resource-group my-rg \
  --sku Standard_GRS

C)

az storage account set \
  --name myaccount \
  --resource-group my-rg \
  --redundancy GRS

D)

az storage account update \
  --name myaccount \
  --resource-group my-rg \
  --redundancy Standard_GRS

Answer Key and Explanations​

Answer Key — Question 1​

Answer: C

GZRS combines replication across availability zones in the primary region with asynchronous replication to a secondary region. This means that even with total unavailability of the primary region, data already exists in the secondary region and failover can be initiated without dependency on prior intervention to move data.

ZRS (A) protects against datacenter or zone failure, but not an entire region. GRS (B) replicates to a second region, but maintains the three primary copies in a single datacenter, without zonal protection. LRS (D) offers no protection beyond the local datacenter.

The critical distinction here is that GZRS is the only one that meets both criteria simultaneously: zonal resilience in the primary and geographic replication for continuity in case of regional failure.

Answer Key — Question 2​

Answer: B

When a storage account failover is completed, the secondary region becomes treated as the new primary region. DNS is updated so that the primary endpoint (myaccount.blob.core.windows.net) points to what was the secondary. As a direct consequence, the -secondary suffix ceases to exist because there is no longer a configured secondary region until Azure provisions a new one, which occurs asynchronously after the failover.

Alternatives A, C, and D describe behaviors that don't exist. Failover doesn't convert to LRS, doesn't permanently disable the endpoint, nor impose a 30-day block. The common misconception is assuming that the post-failover environment preserves the same endpoint topology as the original environment.

Answer Key — Question 3​

Answer: False

ZRS replicates data across three availability zones within a single region. It does not distribute data across distinct regions. The statement confuses ZRS with geo-redundant options like GRS or GZRS.

The protection offered by ZRS covers datacenter, rack, or zone failures within the same region, but doesn't protect against complete regional unavailability. For that, GRS, RA-GRS, GZRS, or RA-GZRS would be needed. Understanding this limitation is essential to not overestimate the resilience level of an architecture based solely on ZRS.

Answer Key — Question 4​

Answer: C

The requirement is explicit: protect against failure of a complete datacenter within the same region, with the lowest possible cost within this constraint. ZRS exactly meets this profile, distributing the three copies across distinct availability zones in the same region.

LRS (A) fails the datacenter protection requirement, as it maintains all copies in the same physical location. GRS (B) exceeds the requirement by adding unnecessary geographic replication, increasing cost. GZRS (D) also exceeds the scope and has the highest relative cost in the table. Choosing GRS or GZRS when the requirement is only zonal is a sizing error that directly impacts cost without adding value to the described scenario.

Answer Key — Question 5​

Answer: A

The correct command to update properties of an existing storage account is az storage account update. The parameter that controls redundancy is --sku, and the correct value for GRS is Standard_GRS.

Alternative B uses create, which would fail if the account already exists or would inappropriately overwrite configurations. Alternative C uses set, which is not a valid subcommand of az storage account. Alternative D uses --redundancy, which is not a recognized parameter by the update command; the correct parameter is --sku. Knowing the exact command syntax is especially relevant in automation scenarios and deployment scripts.