I need to upgrade Standard "D8s v3 (8 vcpus, 32 GiB memory)" to same number of vCPUs and 64GB RAM

Question

I need to upgrade Standard "D8s v3 (8 vcpus, 32 GiB memory)" to same number of vCPUs and 64GB RAM

HCML TEST 40

Hello,

We have Standard D8s v3 (8 vcpus, 32 GiB memory) UK South

Critically, we use nested virtualization - the Azure VM is Win2019 within which we run Hyper-V.

I do realize that the fact we run nested virtualization means we need to be very careful to which Azure VM we upgrade to (at least it mattered a lot when we purchased this VM in 2019).

We basically need to have 64GB of memory, 8 vCPUs, and, ideally, a processor a little more performing.

My questions :

a) Which Azure VM can I upgrade to that will support nested virtualization ? (after reading a lot it looks like D8s v4 is a pathway, or D8s v5)

b) Once I have decided on an upgrade, shut down the VM, and re-sized it, will there be anything I need to reconfigure inside the VM, or will it be seamless ?

M.

Thanmayi Godithi 11,905 Reputation points Microsoft External Staff Moderator

2026-05-01T11:13:57.4166667+00:00

Hi HCML TEST,

Thank you for reaching out on Microsoft Q&A forum.

We are looking into this issue and will get back to you shortly.
HCML TEST 40 Reputation points

2026-05-01T15:00:46.1133333+00:00

Hi Ankit,

That's exactly the detailed and thorough answer I needed (beats the AI answer hands down!!).

I will implement your steps after the users have finished their day this evening, and will report back.

Much Thanks.

M.
Anonymous

2026-05-01T15:42:26.73+00:00

Thank you for your kind words. I look forward to receiving your updates.

If you have any questions or run into any issues, please let us know we're here to help.

Also, please don't miss to click the "Accept Answer" button, it'll look something like below:

Answer accepted by question author

0 additional answers

Your answer

Thanmayi Godithi 11,905 Reputation points Microsoft External Staff Moderator

2026-05-01T11:13:57.4166667+00:00

Hi HCML TEST,

Thank you for reaching out on Microsoft Q&A forum.

We are looking into this issue and will get back to you shortly.
HCML TEST 40 Reputation points

2026-05-01T15:00:46.1133333+00:00

Hi Ankit,

That's exactly the detailed and thorough answer I needed (beats the AI answer hands down!!).

I will implement your steps after the users have finished their day this evening, and will report back.

Much Thanks.

M.
Anonymous

2026-05-01T15:42:26.73+00:00

Thank you for your kind words. I look forward to receiving your updates.

If you have any questions or run into any issues, please let us know we're here to help.

Also, please don't miss to click the "Accept Answer" button, it'll look something like below:

Answer 1

Anonymous

Hi @HCML TEST,

Thank you for posting you query, based on your requirements (8 vCPUs, 64 GiB memory, and nested virtualization support), here is how you can approach this:

#1 Supported VM options for nested virtualization

Nested virtualization in Azure is supported on specific VM series where CPU virtualization extensions are exposed to the guest OS. This includes:

Dv3, Dv4, Dv5 series
Ev3, Ev4, Ev5 series

Since you are looking for 8 vCPUs and 64 GiB RAM, the following are appropriate options:

E8s_v3, E8s_v4, E8s_v5 – these meet your memory requirement and support nested virtualization
D8s_v4 or D8s_v5 – these also support nested virtualization, but they provide 32 GiB RAM, so they would not meet your 64 GiB requirement

From this, E-series SKUs are the correct upgrade path if 64 GiB memory is required.

Note: Before proceeding, we recommend confirming:

The selected VM size is available in UK South region
Your subscription has sufficient quota for the Ev family*

#2 Behavior after resizing the VM

Before resizing as a precaution, since the Dv3 family provides temporary storage, please move your data from the temporary disk to the OS disk or any attached disk. Also, take a snapshot of the OS disk to ensure your data is backed up in case of any issues.

To resize:

Stop (deallocate) the VM
Change the VM size
Start the VM again

After resizing:

The guest OS (Windows Server 2019) will typically detect the updated CPU and memory automatically
In most cases, nested virtualization (Hyper-V) continues to function without additional configuration, provided the new VM size supports it

However, it is important to note:

Azure does not guarantee completely seamless transitions across all scenarios
We recommend validating inside the VM after resize:
- Hyper-V role remains enabled
- Nested VMs start successfully

References:

HCML TEST 40 Reputation points

2026-05-05T00:03:59.4233333+00:00
Hi Ankit,

Urgent family issues prevented me from doing this abut I am just now revising it and a crucial question came to my mind.

You write :

The guest OS (Windows Server 2019) will typically detect the updated CPU and memory automatically

In most cases, nested virtualization (Hyper-V) continues to function without additional configuration, provided the new VM size supports it

My experience of doing physical resizing of a VM host, etc..., is that the most critical part is not so much the CPU and memory, but the network adapter because, in the physical world, that network adapter changes and that in turn destroys all port forwarding rules because one has to re-do all the Powershell commands (e.g. Add-NetNatStaticMapping) to do port forwarding to the nested VMs, and that's a lot of work and testing work.

In this case we have over a dozen port forwarding rules to the nested VMs- so will upgrading the server destroy all these because the network adapter name will change ? In other words is the resizing, from the Azure VM standpoint, purely a vCPU and RAM change, or does it extend to the virtual network adapter ?

M.
Anonymous

2026-05-05T01:08:15.77+00:00
Hello M / @HCML TEST ,

In Azure, the network interface (NIC) is a separate resource that is attached to the VM. Resizing a VM (changing its size) primarily affects the compute layer (CPU/memory allocation) and does not recreate or replace the NIC.

The VM continues to use the same NIC resource after resizing

The NIC remains attached to the VM unless you explicitly detach or replace it

The NIC’s MAC address is tied to that interface and is not expected to change unless the NIC itself is changed or recreated

Meaning resizing is not equivalent to a physical host hardware swap where the network card changes.

While the NIC itself is preserved, there are two things to keep in mind:

Dynamic public IPs may change when the VM is deallocated during resize

Resizing is still a disruptive operation (restart / deallocation), so validation after the change is recommended

As a precautionary measure, recommendation is:

After resize, validate:

Get-NetAdapter (adapter name consistency)

Get-NetNat and Get-NetNatStaticMapping

Confirm nested VMs are reachable through existing forwarded ports

Please note this is simply a precaution not because Azure resize is expected to break networking.

Hope this answers your query, if yes, please do take a moment to click on "Accept Answer" button.
Anonymous

2026-05-06T10:34:25.3966667+00:00

Hi HCML TEST,

Just checking in if you had a chance to review my response shared earlier, do let me know if it answered your query. Also, don't forget to click on "Accept Answer" button.

Answer 2

a) From the provided information, nested virtualization support is explicitly documented for:

ECesv6-series (up to 64 vCPUs, 512 GiB RAM) – this series supports Nested Virtualization and offers sizes with 8 vCPUs and higher memory (for example, Standard_EC8es_v6 has 8 vCPUs and 64 GiB RAM).

So, for an 8 vCPU / 64 GiB configuration with nested virtualization, Standard_EC8es_v6 in the ECesv6-series is a documented option.

Note: Mdsv3 Very High Memory sizes explicitly do not support Nested Virtualization, so they are not suitable for this scenario.

b) The context only provides generic resize guidance and does not describe any required in-guest reconfiguration steps specific to nested virtualization when resizing. It only states that:

To change VM size, choose a new size and then resize the VM.

No additional in-guest reconfiguration requirements are documented in the provided material.

References: