Prices of transactions on Azure Virtual Machine

Question

Hi,

The pricing page mentions transactions cost. Is this section relevant to Virtual Machines? That is, using the OS disk on my VM will cost me more than not using it? If so, how do I translate "I/O transactions" to read/write MBs?

Thanks in advance!

Answer 1

Hi YaronP:

Thanks for reaching out to Microsoft Q&A.

Rather than me writing one more copy of my version of answer to your question, please find the below links which I feel explains better with proper examples.

https://learn.microsoft.com/en-us/answers/questions/48739/virtual-machine-pricing-for-operaing-system-disk

https://stackoverflow.com/questions/12122931/do-azure-vm-pricing-include-storage-in-the-vhd

Please 'Upvote'(Thumbs-up) and 'Accept' as answer if the reply was helpful. This will be benefitting other community members who face the same issue.

Answer 2

Hello, @YaronP ! Update: I received confirmation and have updated my answer below.

Am I charged for I/O transactions on my VM? What about my OS disk?

Azure does not differentiate between OS and Data disks when it comes to charging for transactions. As unmanaged disks are being retired, this answer will address managed disks.

The short answer is that it depends on the disk type (and whether or not you are bursting--see below). Referencing the Azure Pricing Calculator makes this easier to understand in many cases.

The fee is usually pretty small though and using Standard SSD as an example, Azure currently charges $0.002 per 10,000 transactions (reference the pricing page for up to date prices). That's one cent for 50,000 transactions or (assuming my math is correct today) $0.20 for a million transactions (100 transaction units of 10,000 transactions each). Any type of operation against the storage is counted as a transaction, including reads, writes, and deletes.

Some storage types such as Premium SSD v2 and Ultra Disk include throughput. This is also relatively low as well (below is an Ultra Disk maxing out at 25 MB/s):

Bursting is also worth mentioning if you decide to enable that. Busting can improve startup times, help with batch jobs, and address traffic spikes.

• P20 disks and smaller use credit-based bursting which is enabled by default with no additional costs.
• P30 disks and larger allow you to enable on-demand bursting which must be enabled by the user. The cost varies depending on your scenario and I've included references below for more information.

Additional information:

• Managed Disks pricing
• Azure Pricing Calculator
• Managed disk bursting

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