Azure Managed Disks are storage volumes used with Azure Virtual Machines (AVMs). Since there is a requirement for a storage account in Azure to store the virtual images, the users have to manage them on their own. With Azure Managed Disks, there is no need to create Azure Storage Accounts for virtual disks. Azure allows users to specify the disk type and size with the help of Azure Managed Disks. This article will provide an overview of Azure Managed Disks, its benefits, encryption services, and Azure Disk roles and types.
Azure Managed Disks:
Azure Managed Disks are highly scalable and durable storage disks similar to physical disks in an on-premise server. It is used with Azure Virtual Machines (VMs) and it is managed by Microsoft Azure. There are several disk options available for deployment under Azure Managed Disk which include premium Solid State Drives (SSD), standard Hard Disk Drive (HDD), standard SSD, and ultra-disk.
Benefits of Azure Managed Disks
There are several benefits of Azure Managed Disks, which include availability, deployment, and backup. Let’s look at each one in detail:
Availability: Azure Managed Disks are placed in different domains to achieve 99.999% availability, high fault tolerance, durability, and better Service Level Agreement (SLA). This is achieved by storing several replicas of data on different domains, which ensures the persistence of stored data in case other replicas experience issues.
Deployment and Scalability: Azure Managed Disks allows users to deploy up to 50,000 disks per region and up to 1000 virtual machines from the Marketplace images in a single subscription. This feature makes the Azure Managed Disk easy to deploy and scale.
Azure Backup Services: Since Azure Managed Disks store replicas of data with the integration of timestamps and availability zones, this assists in maintaining the backup and managing disk restorations as required. Azure also provides backup retention policies and Azure Disk Backup which manages a snapshot lifecycle for backup.
Encryption in Azure Managed Disk
Azure Managed Disks also offer different types of encryptions to be used with managed disks. These are Azure Disk Encryption (ADE) and Server-Side Encryption (SSE). Azure Disk Encryption provides encryption on the operating system and data. If the operating system is Windows, ADE uses Bitlocker technology to encrypt the drive. However, in the case of Linux OS, ADE utilizes DM-Crypt technology. On the other hand, the SSE service provides default encryption on Azure storage disks for the security needs of any organization.
Azure Disk Types
Azure Storage offers different types of disks for Azure Managed Disks. These include SSD, HDD, and ultra-disks. Standard HDD is the cheapest solution and is useful for non-critical workloads such as development, testing, backup, and recovery workloads. On the other hand, Standard SSD is useful for light to heavy workload and is comparatively pricier than standard HDD. Standard SSD is useful for web servers, application servers, and enterprise applications.
For heavier workloads, Azure Premium SSD and Azure Ultra-Disks are optimal solutions. Premium SSD offers high-performance and is suitable for Dynamics CRM and databases. On the other hand, Azure Ultra-Disks offers low latency and high throughput, making it suitable for SAP and enterprise databases.
Azure Disk Roles
Azure Managed Disks such as SSDs, HDDs, and Ultra-Disks have three types of disk roles: Operating System disks, data disks, and temporary disks. OS Disks are responsible for hosting the virtual machine OS and its disk volume. Each virtual machine is deployed with a single OS disk containing its installed operating system. On the other hand, data disks are in charge of storing data and applications of a particular OS. They are attached to virtual machines and are capable of holding up to 32 TB of data.
The third category of disks, also known as temporary disks, are attached with virtual machines similar to data disks. However, these disks are not responsible for storing important data. Instead, these are used for hosting page files and swap files. As the name implies, data stored on a temporary disk is lost during the redeployment of a virtual machine. In the case of Windows OS, temporary disks are often denoted by the letter D. For Linux machines, the disk is represented as /dev/sdb.
Azure Managed Disks have taken care of the storage hassles that were normally faced by the users. They have provided utmost flexibility to users by providing a greater number of storage accounts under a single subscription with several disk types. At this stage you should have a reasonable grasp of the concepts of Azure Managed Disks, their benefits, disk types, and disk roles!
Happy coding 😀