Blob Lifecycle Management

Manually managing the lifecycle of millions of blobs is impractical. Azure Blob Storage lifecycle management policies let you automate the transition of data between access tiers and the deletion of expired data. This lesson covers how to create lifecycle policies, the rules and filters available, and practical strategies for managing data at scale.

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What Is Lifecycle Management?

Lifecycle management is a rule-based policy that automatically performs actions on blobs based on conditions you define. Instead of writing scripts to move or delete old data, you define rules that Azure executes automatically once per day.

Common Scenarios

• Move logs from Hot to Cool after 30 days, then to Archive after 90 days
• Delete temporary files after 7 days
• Move previous versions to Cool tier after 60 days
• Delete old snapshots after 180 days
• Transition compliance data to Archive after 1 year

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How Lifecycle Policies Work

A lifecycle management policy is a collection of rules. Each rule has:

1. Filters — which blobs the rule applies to (by prefix, blob type, or blob index tags)
2. Actions — what to do with matching blobs (tier change, delete)
3. Conditions — when to perform the action (based on the number of days since creation, modification, or last access)

Azure evaluates all rules once per day. Actions may take up to 24 hours to execute after the conditions are met.

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Creating a Lifecycle Policy

Azure Portal

1. Navigate to your storage account
2. Go to Data management > Lifecycle management
3. Click Add a rule
4. Define the rule name, blob type scope, and filters
5. Add conditions and actions
6. Save the policy

Azure CLI (JSON Policy)

az storage account management-policy create \
  --account-name mystorageaccount \
  --resource-group rg-storage-demo \
  --policy @policy.json

Bicep

resource lifecyclePolicy 'Microsoft.Storage/storageAccounts/managementPolicies@2023-01-01' = {
  parent: storageAccount
  name: 'default'
  properties: {
    policy: {
      rules: [
        {
          name: 'moveToCoolAfter30Days'
          enabled: true
          type: 'Lifecycle'
          definition: {
            filters: {
              blobTypes: ['blockBlob']
              prefixMatch: ['logs/']
            }
            actions: {
              baseBlob: {
                tierToCool: {
                  daysAfterModificationGreaterThan: 30
                }
                tierToArchive: {
                  daysAfterModificationGreaterThan: 90
                }
                delete: {
                  daysAfterModificationGreaterThan: 365
                }
              }
            }
          }
        }
      ]
    }
  }
}

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Policy Structure

A lifecycle management policy is a JSON document with the following structure:

{
  "rules": [
    {
      "name": "rule-name",
      "enabled": true,
      "type": "Lifecycle",
      "definition": {
        "filters": { ... },
        "actions": { ... }
      }
    }
  ]
}

Filters

Filter	Description
blobTypes	Which blob types to target: blockBlob, appendBlob
prefixMatch	Blob name prefixes to match (e.g., ["logs/", "temp/"])
blobIndexMatch	Match blobs by index tag key-value pairs

Actions

Actions can target the base blob, snapshots, or versions:

Action	Applies To	Description
tierToCool	Base blob, snapshot, version	Move to Cool tier
tierToCold	Base blob, snapshot, version	Move to Cold tier
tierToArchive	Base blob, snapshot, version	Move to Archive tier
delete	Base blob, snapshot, version	Permanently delete
enableAutoTierToHotFromCool	Base blob	Auto-move back to Hot if accessed from Cool

Conditions