Blob Capacity metrics explanation


  • I'm trying to understand how blob capacity is calculated for billing. When viewing the blob capacity metric over a period of time the graph moves up and down considerably, which doesn't make sense to me. In the examples below, for a couple of days it registers ~220GB and then falls to ~2GB for a couple of days. Why is it registering only a couple of GB half of the time?

    In this case all of the capacity is consumed by 2 VHDs attached to a VM. For comparison, when looking at used disk space from the VM itself, total used space is ~313GB currently. And that hasn't changed much over the timeline represented in the graphs below.

    Friday, January 11, 2019 4:22 PM

All replies

  • Are your VHD's using standard or premium storage?

    Sam Cogan Microsoft Azure MVP
    Blog | Twitter

    Friday, January 11, 2019 7:35 PM
  • Standard
    Friday, January 11, 2019 8:36 PM
  • To add to the original question and try to make sense out of the invoice, here are some additional considerations.

    The data shown below is for the billing period of 11/23/18 - 12/22/18.

    This is the invoice generated by Azure showing the amount consumed and billed for Standard Page Blob storage.

    This is the CSV downloaded from Azure showing the details for this period. (Only Standard Page Blob entries are shown)

    It's unclear how just 75GB is billed when there is substantially more data being used. From what I gather the Consumed Quantity takes into account deduplication. Would that be enough to explain the difference between the disk usage reported in the VM of ~300GB vs. the billing usage of 75GB?

    Friday, January 11, 2019 9:24 PM
  • hi cmcfarling09, to get the most accurate response/interpretation, I recommend opening a support case with the Azure Billing support team using these steps. If you don't have a support plan, send mail to, include your subscription ID and a link to this thread for context and we will gladly assist you with raising a support ticket.

    Friday, February 1, 2019 4:54 PM