A while ago now I covered Azure’s Reserved Instance (RI) feature and how its use can dramatically reduce the TCO for your Azure VMs. Well this useful feature just got even better! Microsoft are introducing ‘size flexibility for Azure Reserved Instances’
With traditional RI’s you chose the VM instance size (D4s_v3 for example) and how many years you wanted to reserve for. This didn’t really fit with the cloud principles of ‘Starting small and growing’ or being plastic with your environment, growing and shrinking as needed.
The new approach to RI’s will allow you to buy a base RI, again a D4s_v3 and using it as either a full discount towards the VM or partial discount if you upscale/deploy a VM of a larger size. For example (table credit to Microsoft):
|VM name||VM group||Ratios|
All the VMs must be running within the same region for the RI to apply and it’s important to note that although any flavour of OS will be covered (Windows Server, Linux, RHEL) you will still be charged at the appropriate rate for any software running on the VM.
RI flexibility will be enabled by default on existing Azure Reserved Instances within a shared scope. Single scope RI’s can be enabled from the reservation configuration.
A great addition that makes this feature a little more cloud aligned.