Introduction

Azure Storage lifecycle management for blobs allows you to manage blobs efficiently across various tiers and delete them when they are no longer needed. This capability helps you to:

  • Optimize costs: Move infrequently accessed data to cheaper tiers or delete it automatically.
  • Automate workflows: Implement automated policies for data retention and archiving.
  • Ensure compliance: Meet regulatory requirements by managing data for specific durations.

Lifecycle management policies are rule-based and can be applied to individual containers or your entire storage account.

How It Works

A lifecycle management policy consists of a set of rules. Each rule can apply to a subset of blobs in your storage account, defined by a filter.

For each rule, you can define actions that are performed on blobs that meet the rule's criteria. These actions can include:

  • Moving blobs to a different tier: Transition blobs from Hot to Cool, Archive, or back from Cool to Hot.
  • Deleting blobs: Permanently remove blobs after a specified period.

The lifecycle management service evaluates these rules periodically (typically once a day) and applies the defined actions to matching blobs.

Creating Lifecycle Rules

You can create lifecycle rules using the Azure portal, Azure CLI, or PowerShell.

Rule Elements:

  • Name: A unique identifier for the rule.
  • Scope: Applies to either a specific container or all containers in the storage account.
  • Filters: Define which blobs the rule applies to. You can filter by:
    • Blob prefix (e.g., logs/).
    • Blob type (Block blobs or Append blobs).
    • Tags.
  • Actions: The operations to perform.
    • Base actions: For blobs that are not versioned.
      • Transition to Cool (after N days).
      • Transition to Archive (after N days).
      • Delete (after N days).
    • Snapshots and versioning actions: For versioned blobs and snapshots.
      • Transition current and previous versions to Cool (after N days).
      • Transition current and previous versions to Archive (after N days).
      • Delete previous versions (after N days).
      • Delete snapshots (after N days).

Pro Tip

When defining transitions, ensure the duration (N days) is carefully considered. For example, transitioning to Archive might incur retrieval costs and time. Plan your data access patterns.

Example Rule Configuration (Conceptual):

Move blobs starting with archive/ to the Archive tier 365 days after their last modification.

Rule Name: ArchiveOldData Scope: All containers Filter: Blob prefix: archive/ Actions: Transition to Archive: 365 days after last modification

Monitoring Lifecycle Management

You can monitor the effectiveness of your lifecycle management policies through Azure Monitor and the diagnostic logs in your storage account.

  • Azure Monitor: Provides metrics on rule execution and operations performed.
  • Diagnostic Logs: Records detailed information about lifecycle management actions, allowing you to troubleshoot and verify policy execution.

Ensure you have enabled the appropriate logging categories for your storage account to capture lifecycle events.