Azure Virtual Machines Disk Management

This document provides a comprehensive guide to managing disks for your Azure Virtual Machines (VMs). Effective disk management is crucial for performance, cost optimization, and data durability.

Understanding Azure Managed Disks

Azure Managed Disks are the recommended way to manage disks for Azure VMs. They simplify disk management by handling availability, storage infrastructure, and account management for you. Key benefits include:

• High Availability: Managed disks are deployed to a storage redundancy option that you choose.
• Scalability: Easily scale your storage needs without manual intervention.
• Performance Tiers: Choose from Standard HDD, Standard SSD, Premium SSD, and Ultra Disk for varying performance requirements and costs.

Disk Types and Performance

Azure offers several managed disk types, each with different performance characteristics and cost implications:

• Standard HDD: Cost-effective disks for development/test, non-critical workloads, or backup.
• Standard SSD: Consistent performance for I/O-intensive workloads like web servers, lightweight applications, and dev/test environments.
• Premium SSD: High-performance, low-latency storage for I/O-intensive workloads, databases, and production applications.
• Ultra Disk: Highest performance with configurable IOPS and throughput for demanding enterprise applications like SAP HANA, top-tier databases, and high-performance computing.

Common Disk Management Operations

Creating and Attaching Disks

You can create data disks and attach them to your VM during or after creation. Disks can be created from existing VHDs or as empty disks.

Using Azure CLI:

az vm disk attach \
    --resource-group myResourceGroup \
    --vm-name myVM \
    --name myDataDisk \
    --size-gb 100 \
    --sku Premium_LRS

Detaching Disks

Before you can detach a disk, it must be unmounted from the operating system.

Using Azure Portal: Navigate to the VM, go to Disks, select the disk, and click Detach.

Using Azure PowerShell:

# First, detach from the VM
az vm disk detach \
    --resource-group myResourceGroup \
    --vm-name myVM \
    --name myDataDisk

# Then, delete the disk if no longer needed
az disk delete \
    --resource-group myResourceGroup \
    --name myDataDisk

Resizing Disks

You can resize managed disks to accommodate growing storage needs. Note that resizing might require OS-level changes to recognize the new size.

Using Azure Portal: Select the disk, go to Size + performance, and choose a new size.

Using Azure CLI:

az disk update \
    --resource-group myResourceGroup \
    --name myDataDisk \
    --size-gb 200

Disk Snapshots and Images

Snapshots are point-in-time copies of a disk. They are stored as managed disks and are incremental. Images can be used to create multiple identical VMs.

Creating a Snapshot:

az snapshot create \
    --resource-group myResourceGroup \
    --name mySnapshot \
    --source myDataDisk

Best Practices for Disk Management

• Choose the Right Disk Type: Match disk performance to application requirements to optimize costs.
• Use Managed Disks: Always opt for managed disks over unmanaged disks.
• Monitor Disk Performance: Regularly check disk IOPS and throughput metrics to identify bottlenecks.
• Regular Backups: Implement a robust backup strategy using Azure Backup or disk snapshots.
• Disk Encryption: Utilize Azure Disk Encryption for enhanced data security.

Next Steps

Explore more about Azure VM storage options, including file shares and content delivery networks.

• Azure Storage Overview
• Managed disk types