News

Azure Ultra Disk Storage Service Now Generally Available in Some Regions

• By Kurt Mackie
• 08/15/2019

Microsoft announced on Thursday that it now offers the Azure Ultra Disk solid-state drive (SSD) storage service commercially, or at the "general availability" stage, in a few Azure regions.

The service is described by Microsoft as its "next-generation distributed block storage service." It provides storage with high throughput and high input/output (IO) for Azure virtual machines (VMs), particularly for users of the DSv3 and ESv3 VMs series. The service is currently available in three Azure regions, namely East US 2, North Europe and Southeast Asia, although Microsoft also indicated that general availability pricing is planned to start on Oct. 1, 2019.

Users of the Azure Ultra Disk preview will automatically get billed at the general availability rate, starting on that Oct. 1 date, Microsoft's announcement indicated.

Organizations might use Azure Ultra Disks when they need to support "data-intensive workloads such as SAP HANA, top tier databases, and transaction-heavy workloads," this Microsoft document explained.

The storage options available with Azure Ultra Disks range from 4 gibibytes (GiB) to 64 tebibytes (TiB). Throughput options range from 300MB per second to 2,000MB per second. Input/output operations options range from 1,200IOs per second to 160,000IOs per second.

Microsoft is touting the ability to alter the storage of Azure Ultra Disks, as well as their throughputs and IO specifications, as needed. The latter changes can take effect in less than an hour, according to Mark Russinovich, chief technology officer for Azure, in a Thursday announcement:

One key benefit of Ultra Disk Storage is that you can dynamically tune disk performance without detaching your disk or restarting your virtual machines. Thus, you can scale performance along with your workload. When you adjust either IOPS or throughput, the new performance settings take effect in less than an hour.

Russinovich had earlier described Azure Ultra Disks in a September Ignite session, noting that they previously went by the code name "Project Direct Drive." He said back then that "it's code-named Direct Drive because the hosts that the disks are mounted to have information about which servers in the Direct Drive cluster have the relevant pieces of the files of the VHDs [virtual hard disks]."

Microsoft has an Azure Premium Storage service that also uses SSDs, but it's dependent on using the Azure Blob storage cache. In contrast, Azure Ultra Disks use Azure "Locally Redundant Storage" to keep three copies within an Azure Availability Zone. Azure Ultra Disks also use Microsoft's "virtual disk client" technology, which provides metadata on disk mappings. The metadata "enables the client to talk directly to storage servers, bypassing load balancers and front-end servers used for initial disk connections," Russinovich explained. This approach reduces latency and delivers "performance comparable to enterprise flash disk arrays," he added.

Organizations wanting to use Azure Ultra Disks can use it with an existing Azure VM, but the VM needs to be within the same Azure region and Availability Zone, according to Microsoft's FAQ document. Availability Zones are datacenters that Microsoft adds to an Azure region to increase fault tolerance and resiliency. Microsoft began offering Availability Zones commercially in March of last year and announced a regional expansion back in October.

Azure Ultra Disks currently don't yet have support for the Azure Backup service, nor can the Azure Site Recovery service be used with it, according to the FAQ. It also doesn't yet support snapshots or Availability Sets.

Microsoft prices the use of Azure Ultra Disks per hour. The costs depend on the disk sizes and performance configurations selected, according to Microsoft's pricing page.