Azure Blob Storage access tiers: Hot, Cool, Cold, and Archive
Slide deck explaining Azure Blob Storage access tiers (Hot, Cool, Cold, Archive), covering billing behavior, online vs offline tiers, rehydration, cost considerations, early deletion rules, use case scenarios, and decision guidance.
Azure Blob Storage access tiers: Hot, Cool, Cold, and Archive
Introduction to Azure Blob Storage access tiers: Hot, Cool, Cold, and Archive, covering cost optimization based on access frequency.
Azure Blob Storage access tiers: Hot, Cool, Cold, and Archive
Introduction to Azure Blob Storage access tiers: Hot, Cool, Cold, and Archive, covering cost optimization based on access frequency.
Why access tiers exist
Tiers balance storage cost against how often you read data. Match tier to access frequency. Warmer equals easier access, higher storage cost. Cooler equals cheaper storage, higher retrieval costs.
Access tier = billing + behavior
A tier optimizes cost based on how often you access data. Hot: higher storage, lower access costs. Cool/Cold: lower storage, higher access costs. Archive: lowest storage, 'offline' behavior.
Online tiers: immediate reads
Hot, Cool, and Cold are online tiers with immediate access. Online tiers: Hot, Cool, Cold. Immediate content access (no rehydration step). Expect fast reads (milliseconds-level).
Archive = offline + rehydration
Archive requires rehydration before you can read content. You can list metadata (blob exists). You can't read content until rehydrated. Rehydration often takes hours. Faster rehydration can cost more.
Total cost ≠ storage only
Tier choice affects storage, operations, and retrieval-related costs. Storage per GB per month. Transactions (read/write operations). Retrieval charges (cooler tiers). Archive rehydration considerations.
Early deletion: plan tier moves
Moving or deleting too soon can trigger extra charges. Cool: often 30-day minimum. Cold: often 90-day minimum. Archive: often 180-day minimum. Confirm details for your account type.
Access tier vs redundancy
Tiers are about access pattern; redundancy is about copies and resiliency. Tiers: cost plus access expectations. Redundancy: copy placement for resiliency. Locally Redundant Storage (LRS) does not equal a tier. Geo-Redundant Storage (GRS) does not equal a tier.
Daily logs → Hot
Frequent reads usually fit Hot best. Accessed daily. Must be available immediately. Hot reduces access/transaction pain. Cool can backfire with frequent reads.
Monthly restores → Cool
Infrequent but immediate access often fits Cool. Retrieved a few times per month. Still needs immediate availability. Cool: infrequent plus online. Archive is risky for urgent restores.
Years of retention → Archive
Rare access plus long retention often fits Archive. Access is very rare (yearly). Hours-level retrieval is acceptable. Archive optimizes for lowest storage cost. Optional: keep recent data online, archive older data.
When access changes: re-tier carefully
If reads become frequent, moving back to Hot may make sense. Cool → frequent reads: reconsider Hot. Tier changes affect billing behavior. Watch minimum retention / early deletion rules. Confirm timing and account specifics.
Pitfalls + decision checklist
Pick tiers by frequency, urgency, and retention—not storage price alone. Total cost includes storage plus ops plus retrieval. Archive is offline (rehydration needed). Cold is online (immediate access). Checklist: frequency, urgency, retention, cost profile.