Azure Disk Storage

• Block-level storage volumes for Azure Virtual Machines
• Disk Storage is a managed disk that is designed for 99.999% availability.
• You can create 50,000 VM disks for each region.

Features

• Different types of storage options: Standard HDD, Standard SSD, Premium SSD, and Ultra Disk volumes up to 64 TiB.
• OS disk has a maximum capacity of 2,048 GiB
• The maximum size of the data disk is 32,767 GiB.
• Managed disks are integrated with the availability sets to ensure that the VM disks are separated from each other in an availability set to prevent a single failure point.
• You can assign specific permissions for a managed disk to one or more users using Azure RBAC.
• You can use the temporary disk to store data such as page or swap files
• Ephemeral OS disks for stateless applications
• Attach a managed disk to multiple virtual machines (VMs) simultaneously using Azure shared disks.
• With snapshots, you can take a back up of your managed disks at any given point in time.

Disk Types

• Standard HDD
  • Low cost and suitable for backups.
  • Write latencies under 10ms.
  • Read latencies under 20ms.
• Standard SSD
  • Consistent performance at lower IOPS levels.
  • Higher reliability, scalability, and lower latency over HDD.
• Premium SSD
  • High-performance and low-latency disk for VMs.
  • Consistent IOPS, and throughput.
  • Offers disk bursting and can burst their IOPS per disk up to 3,500 and their bandwidth up to 170 Mbps.
  • Peak burst limit of 30 mins
• Ultra Disk
  • High throughput, high IOPS, and consistent low latency disk storage
  • Only supports un-cached reads and un-cached writes
  • Doesn’t support disk snapshots, VM images, availability sets, Azure Dedicated Hosts, or Azure disk encryption.
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  • The integration with Azure Backup or Azure Site Recovery is not supported.

Encryption

• Server-Side Encryption (SSE) is performed by the storage service.
• Azure Disk Encryption (ADE) can be enabled on the OS and data disks.
• Encrypted using 256-bit AES encryption.
• For standard HDDs, standard SSDs, and premium SSDs: disabling or deleting the key will automatically shut down all the VMs with disks using that key.
• If you disable or delete a key, any virtual machines with ultra disks using the key won’t automatically shut down.
• Once you enable end-to-end encryption, temp disks and ephemeral OS disks are encrypted with platform-managed keys.

Pricing

• Managed disk size is billed on the provisioned size.
• Snapshots are charged based on the size used.
• Outbound data transfers incur billing for bandwidth usage.
• You are charged for the number of transactions that you perform on a managed disk (the number of read and write data operations performed).

Azure Blob vs Disk vs File Storage:
https://turon.tutorialsdojo.com/azure-blob-vs-disk-vs-file-storage/

Want to learn more about Azure? Watch the official Microsoft Azure YouTube channel’s video series called Azure Tips and Tricks.

Sources:
https://azure.microsoft.com/en-us/services/storage/disks/
https://docs.microsoft.com/en-us/azure/virtual-machines/windows/managed-disks-overview