Azure Managed Disks Overview

Azure Managed Disks: An Overview

Azure Managed Disks offer highly available and durable block storage for your Azure Virtual Machines (VMs). They are designed to address the storage needs of modern applications, providing features like high performance, scalability, and robust data protection.

Key Benefits of Managed Disks:

Simplified Management: Azure handles all the complexities of disk management, including provisioning, patching, and replication.
High Availability: Data is automatically replicated within an Azure region for enhanced durability and availability.
Scalability: Easily scale your storage capacity and performance as your application demands grow.
Durability: Built for enterprise-grade reliability, ensuring your data is safe and accessible.
Security: Support for encryption at rest and in transit to protect your sensitive data.

What are Managed Disks?

Managed Disks are the recommended way to manage disks for Azure VMs. When you create a VM with Managed Disks, Azure automatically creates and manages the storage account for the disk. This abstracts away the underlying storage infrastructure, allowing you to focus on your applications rather than storage management.

Types of Managed Disks

Azure offers several types of Managed Disks, each optimized for different performance and cost requirements:

Standard HDD: Cost-effective for development/test, non-critical workloads, and backup/restore scenarios.
Standard SSD: A cost-effective solution for web servers, lightly trafficked enterprise applications, and development/test environments requiring more consistent latency than Standard HDD.
Premium SSD: High-performance, low-latency storage for I/O-intensive workloads like production databases, application servers, and critical business applications.
Ultra Disk: The highest performance tier, offering configurable IOPS and throughput for the most demanding workloads, such as large relational databases, NoSQL databases, and transactional workloads.

For a detailed comparison, please refer to the Managed Disk Types documentation.

How Managed Disks Work

Each Managed Disk is an object that represents a virtual hard disk (VHD). These VHDs are stored as Azure Storage resources. When you attach a Managed Disk to an Azure VM, it appears as a local disk to the guest operating system. Azure manages the replication, availability, and reliability of the data stored on these disks.

Example: Creating a VM with Premium SSD Managed Disks using Azure CLI.


az vm create \
    --resource-group MyResourceGroup \
    --name MyVM \
    --image Ubuntu2204 \
    --admin-username azureuser \
    --admin-password  \
    --storage-sku Premium_LRS \
    --os-disk-size-gb 128

Key Concepts

OS Disk: The disk that contains the operating system for your VM.
Data Disk: Additional disks attached to a VM to store application data.
Disk Encryption: Azure Disk Encryption can be used to encrypt OS and data disks.
Snapshots: Point-in-time copies of Managed Disks, useful for backups and disaster recovery.
Availability Zones: Deploy your VMs and their disks across different Availability Zones for even higher resilience.

Managed Disks are a fundamental component of modern cloud infrastructure on Azure, providing a robust and flexible storage solution for a wide range of applications.