Today we are announcing the general availability of on demand capacity reservations for Azure Virtual Machines. This new feature allows you to deploy and manage the compute capacity required to run Azure VMs separately from the VMs themselves.

On-demand capacity reservations create new options for you to better manage your compute capacity needs. During our discussions with Azure customers, they often identify the following scenarios:

• Business-critical applications — use on-demand capacity reservations to protect their capacity, for example when taking these VMs offline to perform updates.
  
  
• Disaster recovery (DR) — set aside compute capacity to ensure a seamless recovery in the event of a natural disaster. The compute capacity can be repurposed to run other workloads whenever DR is not in effect. The VM maintenance can be handled by keeping core images up to date without the need to deploy or maintain VMs outside of DR testing.
  
  
• Special events—claiming capacity ahead of time provides assurance that your business can handle the extra demand.

On demand capacity reservations come with a capacity SLA. Unused reserved capacity and Virtual Machines using reserved capacity are both eligible for Azure Reserved Virtual Machine Instance term discounts. However, Reserved VM Instances and on-demand capacity reservations are very different and offer two separate sets of benefits captured in the table below:

Additional Azure services are integrating with on-demand capacity reservations. The Azure Site Recovery service has public preview support for attaching reserved capacity for DR purposes.  

Existing and future capabilities

The number of Azure Virtual Machines series and sizes supported has increased since the start of the public preview.

Specifically, the following Azure Virtual Machines series are now supported:

• Burstable (B-series VMs)
• General-purpose VMs (Av2, Dv2-series VMs and newer generations including Dv5 and Dasv5-series VMs, including support for both Intel and AMD-based VM sizes)
• Memory-optimized VMs (Ev3-series VMs and newer generations including Ev5 and Easv5-series VMs; both Intel and AMD-based VM sizes)
• Compute-optimized VMs (Fv1-series VMs and newer generations)

Microsoft is finalizing support for additional Azure Virtual Machines series. At this time, we expect previews in Q2/Q3 2022, followed by general availability, for the following VM series:

• Storage optimized VMs (L-series)
• Additional memory-optimized VMs (M-series)
• GPU-enabled VMs (NC-series and NV-series)

Azure also offers VM series using InfiniBand networking: ND, HB, and HC VM series. These series will be supported in the future.

The VM deployment methods supported with on demand capacity reservations during public preview are now supported with general availability: single VMs and Virtual Machine Scale Sets using uniform orchestration mode. Starting today, on-demand capacity reservations for Virtual Machine Scale Sets flexible orchestration mode is in public preview. Please read the documentation to learn more.

Additional Azure services will provide on-demand capacity reservations. For example, Azure Site Recovery has enabled use of reserved capacity for disaster recovery. The Azure Kubernetes Service (AKS) has also released preview support to associate node pools with reserved capacity.  

Resources to get started

There are two demonstration videos currently available:

• Basic feature operation and use with single VM deployments.
• Detailed feature operation and integration with Virtual Machine Scale Sets.

Additionally, you can read the on demand capacity reservation documentation that includes sample code.