increase scope and usage visibility of Azure VM Reserved Instances

Currently Turbo recommends VI purchases at an Account/Subscription level. (it can also narrow in on Billing Families and Regions). Azure permits RIs to be limited to Enterprise, Management Group (that’s a collection of Subscriptions), Subscription or Resource Group.

Buying an RI with RG (or sub) scope is for the business case where an application team has a project – commits to it – and wants cheaper VM costs and wants to ensure the project gets the benefit from the RIs. Azure is contrary when assigning the benefit of the RI. Every hour it assigns the RI benefit in a seemingly random order to the VM Compute usage.  Limiting the scope is the only way to control which VMs are assigned the RIs. This however increases the chance of low RI Utilization - and increases RI Administration.

Two different clients need help managing Reserved Instances in a complex environment.

First business case: The client wants a better way to see which VMs are consuming the Shared RIs – a deeper dive than currently present at the Discount Inventory Screen.

Second business case: More visibility – how to visualize all the RIs at the different levels. Enterprise, Management Group, Subscription and Resource Group. This would help the RI Administrator with decisions like Centralization, Maintaining Utilization, and increasing coverage. An initial idea would be a click into the RI – and show the utilization by Tier. If we can’t find out Management Group – at least which subscriptions/RG are using the RI. 

Third Business Case: Turbo recommends Azure RI purchases scoped at a Subscription level – when there are 4 tiers. 

Can we add documentation or context help something like this. “Scoping the Azure VM reservation to one subscription will bring all the benefits of lower rates to the relevant VMs in this subscription. However unused RIs (if any) will be wasted. To maximize RI utilization, and minimize RI management, consider setting the Scope to more Subscriptions (Shared). A possible consequence is other subscriptions could see more benefit of the RI than the original subscription. The recommendation by Turbo is for the Subscription – but is likely to be a valid action for a wider shared scope. This will depend on the business case.”

Please hack my language anyway you like – setting RIs to individual subscriptions can cause reduced RI Util% and increased RI management.