Storage tiers (Hot, Cool, Archive) in Azure - Step-by-Step Execution

Process Flow - Storage tiers (Hot, Cool, Archive)

Data arrives

↓

Choose storage tier

↓

Hot

↓

Fast access

↓

Higher cost

↓

Data stored accordingly

Data is stored in one of three tiers based on how often it is accessed: Hot for frequent use, Cool for less frequent, and Archive for rare access.

Execution Sample

Azure

storageTier = 'Hot'
if dataAccessFrequency == 'daily':
  storageTier = 'Hot'
elif dataAccessFrequency in ['weekly', 'monthly']:
  storageTier = 'Cool'
else:
  storageTier = 'Archive'

This code decides which storage tier to use based on data access frequency, grouping weekly and monthly as 'Cool'.

Process Table

Step	Data Access Frequency	Condition Checked	Storage Tier Set	Cost Implication
1	Daily	dataAccessFrequency == 'daily'? Yes	Hot	Higher cost, fastest access
2	Weekly	daily? No; weekly/monthly? Yes	Cool	Lower cost, slower access
3	Yearly	daily? No; weekly/monthly? No	Archive	Lowest cost, slowest access
4	Monthly	daily? No; weekly/monthly? Yes	Cool	Lower cost, slower access
5	Never	daily? No; weekly/monthly? No	Archive	Lowest cost, slowest access

💡 Storage tier chosen based on access frequency conditions.

Status Tracker

Variable	Start	After Step 1	After Step 2	After Step 3	After Step 4	After Step 5
storageTier	undefined	Hot	Cool	Archive	Cool	Archive
dataAccessFrequency	undefined	Daily	Weekly	Yearly	Monthly	Never

Key Moments - 2 Insights

Why is 'Cool' tier chosen for monthly access instead of 'Hot'?

Because the condition checks if access is daily first; monthly access fails daily check but passes weekly/monthly check, so 'Cool' tier is selected as shown in execution_table row 4.

Why does 'Archive' tier have the lowest cost but slowest access?

'Archive' is designed for rarely accessed data, so it stores data cheaply but retrieval takes longer, as indicated in the cost implication column of execution_table rows 3 and 5.

Visual Quiz - 3 Questions

Look at the execution_table, what storage tier is set when data is accessed weekly?

A Cool

B Archive

C Hot

D None

💡 Hint

Check row 2 in execution_table where data access frequency is Weekly.

At which step does the condition for weekly/monthly become true for monthly access?

A Step 1

B Step 2

C Step 4

D Step 3

💡 Hint

Look at execution_table rows where monthly access is checked and condition is true.

If data access changes from yearly to daily, how does storageTier change according to variable_tracker?

A From Cool to Archive

B From Archive to Hot

C From Hot to Cool

D No change

💡 Hint

Compare storageTier values for Yearly and Daily in variable_tracker.

Concept Snapshot

Storage tiers in Azure:
- Hot: frequent access, highest cost, fastest
- Cool: infrequent access (weekly/monthly), lower cost, slower
- Archive: rare access, lowest cost, slowest
Choose tier based on data access frequency
Switch tiers to optimize cost and performance

Full Transcript

This lesson shows how Azure storage tiers work by choosing Hot, Cool, or Archive based on how often data is accessed. Hot tier is for daily access with higher cost but fast retrieval. Cool tier is for weekly or monthly access with lower cost and slower retrieval. Archive tier is for rarely accessed data with lowest cost but slowest retrieval. The execution table traces decisions step-by-step for different access frequencies. Variable tracker shows how storageTier changes with dataAccessFrequency. Key moments clarify why monthly access uses Cool tier and why Archive is cheapest but slowest. The quiz tests understanding of tier selection and condition checks.

Practice

1. Which Azure Storage tier is best for data that you need to access frequently and quickly?

easy

A. Premium tier

B. Cool tier

C. Archive tier

D. Hot tier

Solution

1. Step 1: Understand storage tier purposes

   The Hot tier is designed for data that is accessed often and requires fast retrieval.

2. Step 2: Compare with other tiers

   Cool tier is for infrequent access, Archive is for rarely accessed data, and Premium is a performance option but not a tier for access frequency.

3. Final Answer:

   Hot tier -> Option D

4. Quick Check:

   Frequent access = Hot tier [OK]

Hint: Hot tier = frequent access, fastest retrieval [OK]

Common Mistakes:

• Confusing Cool tier with Hot tier
• Thinking Archive tier is for frequent access
• Assuming Premium tier is a storage access tier

2. Which of the following is the correct way to specify the Archive tier for a blob in Azure Storage using Azure CLI?

easy

A. az storage account set-tier --tier Archive

B. az storage blob set-tier --tier Hot

C. az storage blob set-tier --tier Archive

D. az storage blob update --tier Cool

Solution

1. Step 1: Identify correct command for blob tier

   The command to set a blob's tier is az storage blob set-tier.

2. Step 2: Choose correct tier parameter

   To set the Archive tier, use --tier Archive. Setting tier on storage account level is invalid.

3. Final Answer:

   az storage blob set-tier --tier Archive -> Option C

4. Quick Check:

   Blob tier set with az storage blob set-tier [OK]

Hint: Use az storage blob set-tier for Archive tier [OK]

Common Mistakes:

• Trying to set tier on storage account instead of blob
• Using wrong command like az storage blob update
• Confusing tier names or casing

3. Consider this Azure Storage blob lifecycle rule snippet:

{
  "rules": [
    {
      "name": "moveToCool",
      "type": "Lifecycle",
      "definition": {
        "actions": {
          "baseBlob": {
            "tierToCool": { "daysAfterModificationGreaterThan": 30 }
          }
        },
        "filters": { "blobTypes": ["blockBlob"] }
      }
    }
  ]
}

What happens to blobs older than 30 days?

medium

A. They are moved to Hot tier

B. They are moved to Cool tier

C. They are deleted

D. They are moved to Archive tier

Solution

1. Step 1: Analyze lifecycle rule action

   The rule specifies tierToCool for blobs modified more than 30 days ago.

2. Step 2: Understand effect on blobs

   Blobs older than 30 days are automatically moved to the Cool tier to save cost.

3. Final Answer:

   They are moved to Cool tier -> Option B

4. Quick Check:

   30+ days old blobs -> Cool tier [OK]

Hint: tierToCool means move blobs older than X days to Cool [OK]

Common Mistakes:

• Assuming blobs move to Archive instead of Cool
• Thinking blobs are deleted by this rule
• Confusing tierToCool with tierToHot

4. You try to set the Archive tier on an entire Azure Storage account but get an error. What is the likely cause?

medium

A. Archive tier can only be set on individual blobs, not on the whole account

B. You must enable Archive tier feature in the portal first

C. Archive tier requires Premium storage account type

D. Archive tier is only for file shares, not blobs

Solution

1. Step 1: Recall Archive tier scope

   Archive tier is applied per blob, not at the storage account level.

2. Step 2: Understand error cause

   Trying to set Archive tier on the whole account causes an error because it's unsupported.

3. Final Answer:

   Archive tier can only be set on individual blobs, not on the whole account -> Option A

4. Quick Check:

   Archive tier scope = per blob [OK]

Hint: Archive tier applies only to blobs, not entire account [OK]

Common Mistakes:

• Thinking Archive tier needs special enablement
• Assuming Archive tier requires Premium account
• Confusing Archive tier with file share tiers

5. A company stores large video files that are rarely accessed but must be retained for years. They want to minimize storage costs but can tolerate hours of retrieval delay. Which Azure Storage tier strategy should they use?

hard

A. Store videos directly in Archive tier

B. Store videos in Cool tier and move to Archive after 90 days

C. Store videos in Hot tier for fast access

D. Store videos in Premium tier for best performance

Solution

1. Step 1: Identify access frequency and cost needs

   Videos are rarely accessed and cost minimization is priority, so Archive tier fits best.

2. Step 2: Consider retrieval delay tolerance

   Archive tier retrieval can take hours, which is acceptable here.

3. Step 3: Evaluate other options

   Hot tier is costly, Cool tier is more expensive than Archive, Premium is for performance, not cost saving.

4. Final Answer:

   Store videos directly in Archive tier -> Option A

5. Quick Check:

   Rare access + low cost = Archive tier [OK]

Hint: Rarely accessed + low cost = Archive tier [OK]

Common Mistakes:

• Choosing Hot or Premium tier for rarely accessed data
• Using Cool tier without moving to Archive
• Ignoring retrieval delay tolerance