Resized my Azure VM from B4ms to D4as_v4 - Size Not Showing from OS level

Question

I was running into CPU overutilization on one of my VM's. So I decided to upgrade my VM size from B4ms (2vCPUs and 16GB RAM) to D4as_v4 (4vCPUs | 16GB RAM).

Via the Azure Portal Overview page, I can see that the upgraded size is reflecting correctly. However, upon logging in the vCPUs are showing as 2vCPUs and not 4vCPUs.

Compared with my other VM's, these machines are running the exact OS and sizing showing the correct vCPU - 4.

Long story short

My VM shows Standard D4as v4 (4 vcpus, 16 GiB memory) from the Azure Portal but from the OS layer its still running B4ms (2vCPUs and 16GB RAM).

I have tried rebooting the machine, re-deploying to a new host and even check via msconfig and the result shows only 2 (number processors).

Operating system

Windows (Windows Server 2016 Standard)

Size - Standard D4as v4 - vCPUs | RAM 16 GiB

Has anyone ever experienced this before?

Answer 1

Hello Tarneshdeep Singh

Welcome to Microsoft Q&A Platform, thanks for posting your query here.
Based on the issue description, you have resized your Azure VM from B4ms to D4as_v4, but the OS layer is still showing the old size. This can happen if the VM is not properly restarted after resizing.

You mentioned that you have already tried rebooting the machine, but the issue still persists.

Ensure that the Azure Guest Agent running inside the VM is up to date. The Guest Agent is responsible for reporting the VM's configuration to the Azure Portal. You can update the Guest Agent by using the Azure Portal, Azure CLI, or PowerShell commands.

I would recommend you to perform a "Redeploy" operation on the VM. This operation moves the VM to a new node within the Azure infrastructure and can help resolve issues related to VM state.

Ref: https://learn.microsoft.com/en-us/troubleshoot/azure/virtual-machines/redeploy-to-new-node-linux

After the VM is started, please check if the correct number of vCPUs are showing up in the OS layer.

Hope this helps.

Answer 2

Hi @Tarneshdeep Singh Bains

I faced similar issue with one of VM and i came out to be registry setting issue.

I suggest to please raise the ticket with Microsoft and get the feature settings updated inside registry path:

HKEY_Local_Machine>System>CurrentControlSet>Control>SessionManager>MemoryManagement

Hit accept if it helps!