Azure Documentation

Azure Managed Disks Concepts

Azure Managed Disks is a service that simplifies management of Azure virtual machine disks. It handles storage infrastructure for you, so you don't have to manage it yourself.

What are Managed Disks?

Managed Disks are a cloud-based storage solution that abstracts away the underlying storage infrastructure. When you create a virtual machine (VM) with Managed Disks, Azure automatically manages the storage account, replication, and provisioning of the disk. This greatly simplifies disk management and improves reliability and availability.

Key Components of Managed Disks

Disk Types

Azure offers several types of managed disks, each with different performance characteristics and cost:

  • Ultra Disks: High-performance storage for I/O-intensive workloads. Offers configurable IOPS and throughput.
  • Premium SSDs: High-performance, low-latency storage for I/O-intensive workloads, suitable for production workloads.
  • Standard SSDs: Consistent performance for workloads that require lower latency than Standard HDDs, but don't require the performance of Premium SSDs. Good for dev/test, light production.
  • Standard HDDs: Cost-effective, lower-performance storage for applications that are less sensitive to latency, such as backup archives or disaster recovery.

Disk Caching

Disk caching is a crucial feature for improving the performance of managed disks, especially for read-heavy workloads. Azure provides different caching options for different disk types:

  • Read-only: Caches read I/O operations.
  • Read/write: Caches both read and write I/O operations.

The optimal caching strategy depends on your workload's read/write patterns. It's generally recommended to enable caching for Premium SSDs, Standard SSDs, and Ultra Disks to maximize performance.

Disk Encryption

Azure Managed Disks support encryption at rest and in transit. You can choose to:

  • Encrypt with a Microsoft-managed key: This is the default setting. Azure encrypts your data using keys managed by Microsoft.
  • Encrypt with a customer-managed key: You control the encryption keys by storing them in Azure Key Vault. This provides greater control and auditing capabilities.

Disk Operations

Managed Disks support a variety of operations, including:

  • Creating and deleting disks.
  • Attaching and detaching disks from virtual machines.
  • Resizing disks.
  • Creating snapshots of disks.
  • Creating managed disks from snapshots or VHD files.
Important Note: Managed Disks eliminate the need to manage storage accounts for your VM disks. Azure handles the underlying storage, ensuring high availability and durability.

Benefits of Managed Disks

  • Simplified Management: No need to manage storage accounts.
  • High Availability and Durability: Data is replicated for resilience.
  • Performance Options: Choose from a range of disk types to meet workload needs.
  • Security: Built-in encryption options for data protection.
  • Scalability: Easily scale disk capacity and performance.

Use Cases

Managed Disks are suitable for a wide range of Azure workloads, including:

  • Operating system disks for virtual machines.
  • Data disks for applications and databases.
  • Disaster recovery solutions.
  • Development and testing environments.
Tip: For optimal performance, choose the disk type that best matches your application's I/O requirements. Consider Ultra Disks or Premium SSDs for performance-critical workloads.

Next Steps

Now that you understand the core concepts of Azure Managed Disks, you can proceed to learn how to create and manage them: