how do azure vm reservations work for constrained sizes

Hi,

Yes, both E2ds_v5 and E32-8ds_v5 are part of the same instance flexibility group (Edsv5 Series). So if you have quantity: 16 of E2ds_v5 that would cover one E32-8ds_v5 instance.

Please click Accept Answer and upvote if the above was helpful.

Thanks.

-TP

Hi Kuehner, K. (Karl),

Welcome to the Microsoft Q&A Platform! Thank you for asking your question here.

In additional to TP please go through this: Reservations for constrained sizes do not directly come from the underlying series. When you reserve a specific VM size in Azure, the reservation applies only to that exact size, even if it is a constrained size.

If you enable Instance Size Flexibility, your reservation can apply to other VM sizes within the same series as long as they are part of the same instance size flexibility group. For example, if you reserve an E2ds_v5 VM, the reservation can be applied to any other VM within the Edsv5 series that matches the reserved capacity, but the reservation is still tied to the specific resources (like vCPUs and memory) of the VM size you initially reserved.

Please refer to this link for more information: Sizes in series

Both VMs are part of the same group, so if you reserve enough of the smaller VMs (16 of the E2ds_v5), it can cover the usage of one larger VM (E32-8ds_v5).

For detailed information please go through the below links:

Virtual machine size flexibility -Azure Reserved VM Instances - Azure Virtual Machines | Microsoft Learn

Constrained vCPU sizes - Azure Virtual Machines | Microsoft Learn

If you have any further queries, do let us know.

If the answer is helpful, please click "Accept Answer" and "Upvote it."