Quick Note — Recommend a Data Solution for Protection and Durability
AZ-305 › Unit 2 › Design data storage for semi-structured and unstructured data › Recommend a data solution for protection and durability
Quick Note — Recommend a Data Solution for Protection and Durability
When somebody asks an architect "is the data safe?", the honest answer requires unpacking the question into four sub-questions: safe from hardware failure, safe from regional disaster, safe from accidental deletion, and safe from unauthorized access. Azure's storage platform exposes a different control for each: redundancy SKU, geo-replication, soft-delete plus versioning, and network restriction (typically a private endpoint).…
Retrieval target
- Recommend a Data Solution for Protection and Durability
- Closed-book recall
- 5 minutes
- Open the full lesson after a miss
Decision anchors
| Prompt | Compact answer |
|---|---|
LRS (Locally Redundant Storage) | Synchronously replicates 3 copies within a single datacenter in the primary region. Cheapest redundancy. 11 nines durability per year. Survives drive / server-rack failures but not a datacenter or region outage. Pick for non-critical or easily-replaceable data (intermediate ETL stages, dev/test). |
ZRS (Zone-Redundant Storage) | Synchronously replicates 3 copies across 3 Availability Zones in the primary region. 12 nines durability. Survives a single-zone outage (datacenter loss) but not a region outage. Costs more than LRS but less than GRS. Default for HA-required workloads that don't need cross-region DR. |
GRS / RA-GRS (Geo-Redundant Storage) | 3 sync copies in primary (LRS) + 3 async copies in the paired region (LRS in secondary). Total 6 copies, 16 nines durability, region-outage protection. GRS — secondary is read-only only after a failover. RA-GRS — secondary's secondary endpoint is read-anytime (different URL, slight lag). Add 'RA-' when you need DR-region reads without a failover. |
GZRS / RA-GZRS (Geo-Zone-Redundant) | 3 sync copies across primary-region AZs (ZRS) + 3 async copies in the paired region (LRS). Combines zone-failure tolerance in primary with region-failure tolerance via secondary — best protection of all storage redundancy options. 16 nines durability. Add 'RA-' for read-anytime access to secondary. Pick for mission-critical workloads where any failure mode is unacceptable. |
Read the answers once, then cover the right-hand column and reconstruct each one from the prompt. A useful answer names the requirement, the recommended control or service boundary, and the nearest alternative it rejects. If you can only recognize the answer after seeing it, retrieval is not yet secure.
Ninety-second explanation
Without notes, explain:
- What requirement signals this learning objective rather than a neighbouring one?
- Which two solution families are most likely to be compared?
- Which hard constraint eliminates the strongest distractor?
- What identity, network, data, or failure boundary must appear in the design?
- Which operational test would prove the recommendation works?
Then compare your explanation with the full lesson. Record the missing decision rule—not merely the missed product name—in your error log.
When to open the full lesson
Open the curriculum-linked lesson when you cannot explain a comparison, when a scenario depends on a numeric limit or SKU feature, or when the service is on a retirement path. Use current Microsoft Learn documentation for availability, limits, pricing, naming, and migration milestones; the quick note is intentionally compact.
Source and freshness
Derived from the linked AZ-305 lesson and retrieval deck, grounded in both attached course sources. Reviewed 2026-08-02. Current Microsoft documentation controls changing product contracts.