Azure Disk Pricing - Different classes for disk and disk operations

Question

Hello, I'm trying to better understand the cost of Azure Disks, and there is one point that is not clear from the cost management page.
I understand that disks (Standard SSD) are defined by a class (E1, E2, E3, etc.), and each class has two main cost components:

• Disk size
• Disk operations (expressed as transaction units, with an hourly cap since March 2023)

The thing that is not clear to me, is why in my cost reports, I have two different classes assigned to the same disk for Disk size and Disk operations.

If you check the screenshots below, as an example, I have two disks, one of class E2 and the other of class E6, but both of them are billed as class E4 with respect to Disk Operations.

Can someone please explain to me why?

Answer 1

Hi Tommaso , The discrepancy in your Azure cost reports, where disks of different classes (E2 and E6) are billed as class E4 for disk operations, might be due to billing simplifications. Azure often groups similar classes with similar characteristics into a common billing class to simplify pricing structures. While your disks may be technically of different classes, the billing system may categorize them under a single class, in this case, E4, for the purpose of charging disk operations. Always check Azure's official documentation or consult Azure Support for specific details. Regards, Saravanan Ganesan.

Answer 2

@Tommaso Sardelli Thanks for raising this good question. Welcome to Microsoft Q&A Forum,
Thank you for posting your query here!

Firstly, Apologies for the delay response! Based on your scenario, I would recommened to please contact Azure Billing & Subscription team would be the best to provide more insight and guidance on this scenario: https://azure.microsoft.com/en-us/support/options/ it's free, and it's the best choice for you. They will provided you detailed information on your billing based on region , usage and many more.

Additional information:

The total monthly price of a Standard SSD disk has two components:
(a) the storage cost associated with the disk size and
(b) a variable component that depends on the number of transactions per hour that are taking place during the month.

For example, if you select a 4 GiBs E1 Standard SSD SKU, with locally redundant storage (LRS), and perform an average of 4,000 transactions per hour, your total price will be (a) $0.30 / month + (b) 4,000 transactions per hour * ($0.002/10,000 transactions) * 730 hours per each month = $0.30 + $0.584 = $0.884 / month. Note: 730 hours per month is calculated by dividing the total number of hours in a year 24 hours * 365 days divided by 12 months = 730 hours in a month. Conversely, if you selected the same disk size, with locally redundant storage (LRS), and your workload performed 8,000 transactions per hour, your total price will be (a) $0.30 / month + (b) $1.00 = $1.30 / month. In other words, the additional 8,000 – 6,800 = 1,200 transactions per hour would be offered at no additional charge.

• The charges will be pro-rated on an hourly basis using the monthly price. For instance, Premium SSD for P15 is $34.56 (price may vary per region). For October, you will be billed per $34.56/(31 days x 24 hours) = $0.047/hour
• The pricing shown is the monthly price. How do you charge if the Managed Disk is used less than one month?The charge uses the monthly pricing according to the hours and proportional cost.
• Storage capacity is billed in units of the average daily amount of data stored, in gigabytes (GB), over a monthly period. For example, if you consistently used 10 GB of storage for the first half of the month, and none for the second half of the month, you would be billed for your average usage of 5 GB of storage.
• https://stackoverflow.com/questions/75065814/cost-management-question-azure-disk-storage-cost

Please let us know if you have any further queries. I’m happy to assist you further

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