Azure Virtual Machines - Managed Disks

Managed Disks

Managed Disks are a new Azure storage service that uses Azure Resource Manager to manage the disks. With Managed Disks, you no longer need to manage the storage accounts that VMs use. You just specify the size and performance characteristics, and Azure handles the rest.

Simplified Azure Managed Disks Architecture

Key Benefits of Managed Disks

Simplified Management: Azure manages the underlying storage accounts, reducing operational overhead.
High Availability: Managed Disks are designed for 99.999% availability with redundancy options like Availability Zones and Zone-Redundant Storage (ZRS).
Scalability: Easily scale disk performance and capacity up or down as your needs change.
Enhanced Security: Support for encryption at rest and in transit.
Cost-Effectiveness: Pay only for what you provision, with options for different performance tiers.

Types of Managed Disks

Azure offers several types of Managed Disks to cater to different performance and cost requirements:

1. Standard HDD (Hard Disk Drive)

Offers the lowest cost per GB.
Suitable for development/test environments, non-critical workloads, and applications that don't require high IOPS or throughput.
Performance varies based on the size of the disk.

2. Standard SSD (Solid State Drive)

Provides consistent performance at a lower cost than Premium SSDs.
Ideal for web servers, lightly trafficked applications, and development/test environments where higher performance is needed than Standard HDD.
Offers better IOPS and throughput compared to Standard HDD.

3. Premium SSD (Solid State Drive)

High-performance, low-latency storage.
Excellent for I/O-intensive workloads, production applications, and databases that require fast and consistent performance.
Offers predictable and repeatable performance characteristics.

4. Ultra Disk Storage

The highest-performance disk offering.
Designed for I/O-intensive workloads like SAP HANA, top-tier SQL and NoSQL databases, and large-scale analytics.
Allows you to provision IOPS and throughput independently of disk size.

Creating and Managing Managed Disks

Managed Disks can be created and managed through the Azure portal, Azure CLI, PowerShell, or ARM templates.

Example: Creating a VM with Managed Disks using Azure CLI

To create a VM and automatically create Managed Disks for its OS and data, you can use a command similar to this:


az vm create \
  --resource-group MyResourceGroup \
  --name MyVM \
  --image UbuntuLTS \
  --admin-username azureuser \
  --admin-password 'YourPassword123' \
  --storage-sku Standard_LRS \
  --data-disk-sizes-gb 100 200

In this example:

--storage-sku Standard_LRS specifies the type of managed disk (e.g., Standard Locally Redundant Storage).
--data-disk-sizes-gb 100 200 creates two data disks of 100GB and 200GB respectively.

Key Considerations

Disk Size and Performance: Choose the disk type that best matches your application's IOPS and throughput requirements.
Redundancy: Select LRS (Locally Redundant Storage), ZRS (Zone-Redundant Storage), or GRS (Geo-Redundant Storage) based on your availability needs.
Cost: Different disk types have different pricing models.
Migration: Azure provides tools to migrate existing unmanaged disks to managed disks.

Tip: For production workloads, it is strongly recommended to use Premium SSD or Ultra Disk Storage for your operating system disk to ensure optimal performance and responsiveness.

Explore the official Azure documentation for more in-depth details and advanced configurations.