Let me try bring some insight on Azure storage reservations. If you have not read my previous blog posts on VM reserved instance, please read it here. You can save on storage cost for blob data with Azure Storage reserved capacity. It covers both for block blobs and Data Lake Gen2. You must be owner of the subscription or EA admin if it is EA and you must a admin agent or sale agent to buy Azure Blob Storage reserved capacity. I tried to bring information from different MS article to one place with bullet points to help you on this.
Importantly, a reservation covers only the data stored in the subscription, it does not cover other actions like early deletion, operations, bandwidth and data transfer charges. You may note the below points when you think about the reserving the Azure storage.
- It is available for single or multiple subscriptions.
- The scope is applied at the subscription selected but you cannot limit to a specific storage account.
- A reservation cannot be split across multiple subscription.
- As soon as you buy, the capacity charges that match the reservation attributes are charged at the discounted rates.
- It is valid only for data stored in that region, access tier and redundancy options.
- You can purchase the storage reserved capacity in 100 TB or 1 PB per month for 1- or 3-year term.
Note: It is not available for premium storage accounts, GPv1, Data Lake Storage Gen1, page blobs, Queue storage, table storage and Azure Files.
Storage reservation option is not available for all the Azure storage. The available types, tiers and redundancy options are provided below.
- Account type – Standard Storage and Blob storage accounts
- Tiers – Hot, Cool, and Archive
- All the redundancy like LRS, ZRS, GRS, GZRS etc.
You need to consider below points when you can exchange or refund or expiry of the storage reservations.
- No limits on the number of exchanges you can make.
- No fee applicable with an exchange.
- You can change a reservation property such as family, series, version, SKU, region, quantity, and term with an exchange.
- The new reservation that you purchase must be equal or greater value than prorated credit from the original reservation.
- A Storage reservation can be exchanged only for another Azure storage reservation.
- The new reservation purchased as part of exchange has a new term starting from the time of exchange.
- You a cancel reservation any time and you will get prorated refund based on the remaining term but there will be 12% early termination fee applicable.
- When it expires, the storage in the scope will be applied with PAYGO rate.
- You will get an email notification 30 days prior to the expiry.
It is important to know how Microsoft will process the dollars associated with cancel and refund.
For EA customers
- Money is added to the monetary commitment for exchanges and refunds if the original purchase was made using one.
- If the original purchase was made as an overage, Microsoft issues a credit memo
For PAYGO invoice payments
- The original reservation purchase invoice is canceled and then a new invoice is created for the refund.
- For exchanges, the new invoice shows the refund and the new purchase.
- If you only refunded a reservation, then the prorated amount stays with Microsoft and it’s adjusted against a future reservation purchase.
For PAYGO credit card payments.
- The original invoice is canceled, and a new invoice is created.
- The money is refunded to the credit card that was used for the original purchase
If we analyse our usage smartly and design our infrastructure to utilize the Azure reservation effectively then you can save cost. I hope this blog will help you planning reservation option. You may also read my other blog post on disk reservation here.