Standard SSD Disks for Azure Virtual machine workloads

Standard SSD Disks are now generally available. Please refer to our announcement of a new type of durable storage for Microsoft Azure Virtual machines. Standard SSD Disks are a cost-effective storage option optimized for workloads that need consistent performance at lower IOPS levels. The new Azure Standard SSD Disks store data on Solid State Drives (SSDs), like our existing Premium Storage Disks. Whereas our Standard HDD disks store data on Hard Disk Drive (HDD). With the addition of Standard SSD, Azure now offers three types of persistent Disks for use with Azure Virtual machines, optimized for different workload requirements: Premium SSD Disks, Standard SSD Disks, and Standard HDD Disks.

Following is a summary comparing Azure Disk types.

Benefits of Standard SSD Disks

We designed Standard SSD Disks to improve the performance and reliability of Standard Disks. This new disk offering combines the elements of Premium SSD Disks and Standard HDD Disks to form a cost-effective solution best suited for applications like web servers which do not need high IOPS on disks. Today many of these workloads use HDD-based disks to optimize the cost. However, HDD disks are typically less performant and less reliable than SSD based disks. In principle, all laaS workloads should leverage SSD-based disks, and experience the better performance, better reliability, and overall smoother operations that the technology enables. Standard SSD Disk is our answer to this, and the new disk type is uniquely designed to meet the specific workload requirements at optimal cost.

Virtual machines

Standard SSD Disks are designed to work with all Azure Virtual Machine SKUs. If you are using an A-series VM, or N-series VM, or D-series VM, or any other Azure VM series, you can use Standard SSD Disks with that VM. With the introduction of Standard SSD, we are enabling a broad range of workloads that previously used HDD-based disks to transition to SSD-based disks and experience the consistent performance, higher availability and an overall better experience that come with SSDs.

Standard SSD Managed Disk sizes

Standard SSD Disks are offered as a type of Managed Disks. Unmanaged Disks and Page Blobs are not supported on Standard SSD. The following Disk sizes will be offered a preview.

Standard SSD Disks support all service management operations offered by Managed Disks. For example, you can create Managed Snapshots from Standard SSD Managed Disks in the same way you create snapshots for Managed Disks. Refer to the Managed Disks documentation for detailed instructions on all disk operations.

Performance

Standard SSD disks are designed to provide single-digit millisecond latencies for most IO operations. Also, the above disk sizes are designed to deliver up to 500 IOPS and 60 MBPS throughput similar to the HDD disks. Actual IOPS and Throughput may vary sometimes depending on the traffic patterns. Standard SSD disks will provide more consistent performance than the HDD disks with the lower latency.

Premium SSD disks, on the other hand, perform better than Standard SSD disks, with very low latencies, high IOPS/throughput and even better consistency with provisioned disk performance, and it is the recommended disk type for all other production workloads.

Like the existing Premium SSD Disks, Standard SSD Disks also use IO Unit size of 256KB. If the data being transferred is less than 256 KB, it is considered 1 I/O unit. Larger I/O sizes are counted as multiple I/Os of size 256 KB. For example, a 1,100 KB I/O is counted as five I/O units.

Highly durable and available

Standard SSD disks are built on the same Azure Disks platform which has consistently delivered high availability and durability for disks. Azure Disks are designed for 99.999 percent availability. Like all Managed Disks, Standard SSD disks will also offer Local Redundant Storage (LRS). With LRS the platform maintains multiple replicas of data for every disk and has consistently delivered enterprise-grade durability for IaaS disks, with an industry-leading ZERO percent Annualized Failure Rate.

Pricing

Refer to the Price details for the new Standard SSD Disks that are available. Similar to Standard HDD Disks, billing is based on disk size and actual transactions (I/O units).

Getting started

You can create and manage Standard SSD disks in the same way as the regular Managed Disks. Please use Azure Resource Manager (ARM) templates to deploy VMs with Standard SSD Disks. Below are the parameters needed in the ARM template for creating Standard SSD Disks:

• apiVersion for Microsoft.Compute/virtualMachines must be set as “2018-04-01” (or later)
• Specify storageAccountType as “StandardSSD_LRS” for creating a Standard SSD Disk.

You can convert your existing Managed disks to Standard SSD. Refer to Convert Azure managed disks storage from standard to premium, and vice versa for the general guidelines for converting Managed Disks. Use the value AccountType StandardSSD_LRS to update the disk type to Standard SSD. 

In the coming weeks, we will enable services like Backup/ASR for Standard SSD disks. Refer to Managed Disks documentation for detailed instructions on all disk operations. Standard SSD Disks is currently available in all regions.

Please refer to Disks FAQ document for questions on Standard SSD.