Unable to add the disk in Azure Scale set.


Hello Guys,


I was unable to add a disk in scale Set. when I try to add a disk in scale set so it showing in the storage section in scale set, but when I try it into the VM using RDP so it not showing there. also, the disk is not showing into the Diskmgmt.msc.

8 Replies

@Prashant Sharma, when you add a data disk to a scale set, you must update its instances. If your instances show as not having the latest model, you must update them. The "latest model" in a scale set refers not only to the reference image but also to other scale set properties, such as data disks.


Hello Hspinto, 

Thank you for your reply,

but how to process it. I mean step by step process.?

@Prashant Sharma, it is a very easy process - one liner Powershell/CLI. Please, look at this document:


You have to do repeat the operation for each one of the VM Scale Set instances (VMs).


Make sure you are not using the "reimage" option, as it will recreate your VMs - which is not needed in your use-case.



Hello Hspinto,


I already tried this before posting this query.

but this is not working my friend, after this situation is same, the disk is not showing.

best response confirmed by Prashant Sharma (Contributor)

If your VMSS is in a state similar to what follows:


1. Data disk attached




2. VM instances updated to the latest model



Then you should see the disk in Disk Management




Are all the instances updated to the latest model? Did you scroll down the Disk Management window to see additional disks?


If all the above is true, can you re-image your instances (losing your current OS state, i.e., recreating the VMs)?


Hello Hspinto,

Thank you so much man.

Now it is working.

so one thing more,

when scale out rule is working and its increasing Instances, so at that time Disks are automatically updated in instances or not?

@Prashant Sharma, when the scale set increases the instance count, the new VMs will come with the data disk attached, as per the scale set model - no need to worry about updating those new instances.



Thank you so much hspinto