When resizing a disk - how long will it take to complete?

HBK 1 Reputation point


We have a client who requires one of their Virtual Machine data disks to be increased from; Premium SSD 256GB to a Premium SSD 512GB.

The only issue with this is we do not know how long this process will take, and thus can not tell them exactly how long their sites will be down.

Approximately how long will this process take for the disk to be increase? i.e. 5 minutes or 2 hours?

Thank you

Azure Disk Storage
Azure Disk Storage
A high-performance, durable block storage designed to be used with Azure Virtual Machines and Azure VMware Solution.
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  1. Sumarigo-MSFT 44,496 Reputation points Microsoft Employee

    @HBK The disk type conversion is instantaneous. You can start your VM after the conversion.

    when you are resizing the disk, 2 parts are there now:

    1 Size change in terms of actual space like 256 to 512
    2 You will keep the 256GB disk size the same, but you can increase its performance to the same level of p20 (512) disk.
    So I believe you are referring to the actual disk size change. In that case, there should not be much issue unless he encounters any allocation failure while starting or deallocating the VM and post resizing the disk from the portal, then you need to expand the disk from "Disk Management" in the VM.

    Additional information: In most cases, the desired new VM size is supported on the current hardware cluster hosting the VM. In this case, resizing a VM should not take more than a few minutes, since Azure only needs to change the metadata of the VM and allocate the new size. These are only administrative host actions. In these cases, the Azure only need to restart the VM if it was running.

    Hope this helps!

    Kindly let us know if the above helps or you need further assistance on this issue.


    Please don’t forget to "Accept the answer” and “up-vote” wherever the information provided helps you, this can be beneficial to other community members.

  2. Saurabh Dhande 21 Reputation points


    You will require 5-10 mins only to expand the disk from portal and expand it from OS side.

    Please mark upvote, if fine useful.

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