How to increase disk size on a Azure SQL VM server?

Question

How to increase disk size on a Azure SQL VM server?

X-Box-11-2021 385

Hi All,

Yesterday, I was asked to increase disk size on a VM in Azure. I’ve done that many times so in terms of taken steps I didn’t do anything new.

Stopped a VM.
Resized the disk.
Started VM.

When I opened Disk Management to my surprise I found that the disk I was need to increase remained unchanged. Instead another disk called SQLVMStoragePool1 was increased and it is showing as a storage pool. After doing some search I found that the VM was provisioned as an SQL Server 2022 on Windows Server 2022 in Azure Market Place that seems by default attaches that storage pool.

The issue is I can’t resize the disk that is running out of space because it is not listed under VM \ Disks in Azure portal.

If someone knows how to do that please advise.

Thanks.

chrischin 915 Reputation points Microsoft Employee

2025-03-19T01:52:56.6133333+00:00

Would you be able to post screenshots of both the disks blade from the Azure Portal as well as Disk Management (with disk needing expansion identified)?
X-Box-11-2021 385 Reputation points

2025-03-19T03:59:23.69+00:00

Hi @chrisching

I need to increase\resize disk 4 SQLVMDATA (F:).

For testing purpose this server was restored in test environment and the restored VM doesn't have SQLVMStoragePool1 so my resize yesterday seems somehow cause appearance of it on the server.

If the screenshot look not clearly visible I will re-upload them.
Akshay kumar Mandha 3,390 Reputation points Microsoft External Staff Moderator

2025-03-19T11:33:46.7733333+00:00

Hi X-Box-11-2021,
Based on your query, I understand your concern I'm looking into your query How to increase disk size on a Azure SQL VM server just allow me sometime will provide update on this soon

2 answers

Your answer

chrischin 915 Reputation points Microsoft Employee

2025-03-19T01:52:56.6133333+00:00

Would you be able to post screenshots of both the disks blade from the Azure Portal as well as Disk Management (with disk needing expansion identified)?
X-Box-11-2021 385 Reputation points

2025-03-19T03:59:23.69+00:00

Hi @chrisching

I need to increase\resize disk 4 SQLVMDATA (F:).

For testing purpose this server was restored in test environment and the restored VM doesn't have SQLVMStoragePool1 so my resize yesterday seems somehow cause appearance of it on the server.

If the screenshot look not clearly visible I will re-upload them.
Akshay kumar Mandha 3,390 Reputation points Microsoft External Staff Moderator

2025-03-19T11:33:46.7733333+00:00

Hi X-Box-11-2021,
Based on your query, I understand your concern I'm looking into your query How to increase disk size on a Azure SQL VM server just allow me sometime will provide update on this soon

Answer 1

chrischin 915 Microsoft Employee

It is possible that Disk 4 is an unmanaged disk and that is why it does not show in the Azure Portal VM Disks screen. You could look through your Storage Accounts for blobs that are .vhd files.
Is this SQL on IaaS deployment part of a Windows Failover Cluster? If so, Disk 4 could be a cluster drive that is currently owned by one of the other members of the SQL cluster. You could check by seeing if Windows Failover Cluster role is installed and if the Windows Failover Cluster manager app is installed. Running it would show you any cluster disks.
Last thought is that it is a Shared Disk as described here - https://learn.microsoft.com/en-us/azure/virtual-machines/disks-shared-enable?tabs=azure-portal

X-Box-11-2021 385 Reputation points

2025-03-19T20:03:50.3633333+00:00

Hi @chrischin

For all your assumptions the answer is definite No.

It is definitely managed (at least i don't see a storage account with unmanaged disk)

The SQL server is not part of the failover cluster.

It is not a shared disk.

This is what I see in the Server Manager.
chrischin 915 Reputation points Microsoft Employee

2025-03-20T00:22:49.0933333+00:00

Looks like a Storage Spaces storage pool. What's atypical here is that it is only comprised of a single physical disk. Commonly, many smaller disks are pooled together to create a larger volume.

See if you can determine if the single physical disk there is in fact your Disk 2 in your Disk Management screenshot by looking at its details. If it is, you can go back to Disk Management, right-click on the Disk 2 volume and select Extend Volume to aborb that extra 1 TB of unallocated space to it. Then you can come back to Storage spaces and should see in the bottom right area that the physical disk has grown to 3 TB. After that, on the bottom right, where it says Virtual Disks, you can left click the Virtual Disk and select Extend Volume, to grow it to 3 TB. Finally, go back to Disk Management where you should see unallocated space appear for Disk 4 where you can right-click and choose Extend Volume there.
Akshay kumar Mandha 3,390 Reputation points Microsoft External Staff Moderator

2025-03-20T02:05:28.6033333+00:00

Hi X-Box-11-2021,
As per the documentation, resizing a custom disk might not be possible if it's part of a storage pool. The documentation indicates that to increase the capacity, you would need to expand the storage pool by adding more disks, as stated in the referenced documentation. Please see the screenshot (SS) below for clarification.
https://learn.microsoft.com/en-us/windows-server/storage/storage-spaces/overview
First, attach a new disk to the VM in the Azure portal. Log into the VM, initialize the disk in Disk Management without creating a volume, and add it to the storage pool via Server Manager. Expand the virtual disk inside the pool to increase its capacity. Please refer the below documentation for more details
https://learn.microsoft.com/en-us/azure/virtual-machines/windows/attach-managed-disk-portalhttps://learn.microsoft.com/en-us/windows-server/storage/disk-management/extend-a-basic-volumeand
also refer similar community question and answer mentioned by below
https://learn.microsoft.com/en-us/answers/questions/1659570/how-to-expand-a-virtual-disk-in-a-storage-pool-on
X-Box-11-2021 385 Reputation points

2025-03-20T07:28:28.5+00:00

Hi @chrischin

In the Disk Management if I right-click disk 4 and select Extend Volume I get this:

It looks like Disk 2 1048575MB is related to 1024GB Unallocated space.

Logically adding that space should increase disk 4 size.
chrischin 915 Reputation points Microsoft Employee

2025-03-20T18:10:35.65+00:00

Yes, that is what I am saying - Disk 4 is a Storage Spaces storage pool that is built from Disk 2. We can expand it by making Disk 2 larger; you have 1 TB of unallocated space that you can use to grow Disk 2 which will in turn become +1 TB of unallocated space on Disk 4 where you can extend it to become 3 TB total. Or you can do what the other contributor is saying, which is to attach an additional disk to the VM and add it to this storage pool so that it is made up of 2 different disks instead of just Disk 2. The new disk size will be the sum of the two disks.
X-Box-11-2021 385 Reputation points

2025-03-21T09:22:11.7766667+00:00

Hi @chrischin

Even though the server is protected by few times per day backup I still would like to ask if it is safe to do this.

I tried to reproduce this scenario in Hyper-V but in Azure it seems works differently.

I'm not trying to put responsibility on you but just wandering what is your opion or experience.

Also, the other thing that bothers me is if nobody created that storage pool manually could it be created from Azure portal and applied to the VM either automatically during provisioning? Could it be triggered by resizing the disk?
Akshay kumar Mandha 3,390 Reputation points Microsoft External Staff Moderator

2025-03-21T11:14:16.6666667+00:00

Hi X-Box-11-2021
as per your latest comment When you create the sql server vm it will automatically create the sql storage pool
chrischin 915 Reputation points Microsoft Employee

2025-03-21T14:10:23.0033333+00:00
Hi X-Box-11-2021,

Storage Spaces in the cloud is really only advantageous to get more performance out of the disks by having multiple disks or to posture for establishing a failover cluster. It was more important on-prem when resources were limited, and we didn't have the scalability and elasticity of cloud. In Azure, we can increase the size and performance of a normal disk dynamically and have other high availability options. A Storage Space with a single drive seems like a hassle and not much benefit.

If you wanted to see what happens first, you could replicate this machine and its drives into an isolated VNET, logon to it, and go through those steps first to see what would happen. You could try the expansion option above as well as the alternative of adding an additional disk to the Storage pool. You could leverage the backups you already have or make new snapshots:

Create Disk Snapshots:

In the Azure portal, navigate to your existing SQL VM.

Select the disks (OS and data disks) and create snapshots for each.

Create Managed Disks from Snapshots:

Use the snapshots to create new managed disks.

Deploy a New VM:

Create a new VM in a new isolated vnet using the managed disks created from the snapshots.

Configure Networking:

Ensure the new VM is deployed in the isolated vnet.

Attach Data Disks:

Attach the data disks to the new VM.
Akshay kumar Mandha 3,390 Reputation points Microsoft External Staff Moderator

2025-03-24T07:29:52.18+00:00

Hi X-Box-11-2021,
Could you please verify the latest comment mentioned by chrischin about the storage space and how manage please review it once
Akshay kumar Mandha 3,390 Reputation points Microsoft External Staff Moderator

2025-03-25T09:23:00.3066667+00:00

Hi X-Box-11-2021,
any update on previous response please let me know if you have any other query

Answer 2

X-Box-11-2021 385

I contacted MS Azure support team and finally have the steps to address the issue.

In my case after I resized the data disk which triggered creation of storage pool I had two options:

Attach another disk and add it to the existing one. In this case I would get the sum of the current data disk size + new data disk size.
Attach another data disk, mark the current disk as retired and then it out of the storage pool.

I hope this will be helpful for someone in the future.

Akshay kumar Mandha 3,390 Reputation points Microsoft External Staff Moderator

2025-04-03T09:11:48.4233333+00:00

Hi X-Box-11-2021,
I'm glad to hear that the issue has been resolved for you! To assist others who might face a similar challenge, since you, as the original poster, are unable to accept your own answer, I’ll reshare it, and you can then mark it as the accepted solution. This will ensure it’s easier for others to locate. Could you please confirm so I can proceed with reposting the solution? Let me know!
Wan Aminuddin Wan Doshah 0 Reputation points

2025-04-21T09:06:10.8566667+00:00

Hi @X-Box-11-2021 ,

I'm currently facing the same issue as you. Would you mind sharing the detailed steps you took to resolve it?

Thanks in advance for your help!
X-Box-11-2021 385 Reputation points

2025-04-23T08:16:57.41+00:00
@Wan Aminuddin Wan Doshah

Attach new data disk in Azure portal.

Inside a server in the Disk Management initialize the new disk.

Go to the Server manager - Storage Pools

Add physical disk

Run PS command Get-StoragePool -Friendly name 'Storage_Pool_Friendly_Name' | Get-Physical-Disk | Format-List UniqueId, Size,VirtualDiskFootPrint

Set-PhysicalDisk -UniqueId "Disk_Unique_Id" -Usage Retired <- the one you want to replace.

Run Repair-VirtualDisk -FriendlyName 'Vitual_Disk_Friendly_Name'

Make sure that storage job is finished (Get-StorageJob) and retired disk footprint value is 0 (Get-Physical-Disk | Format-List UniqueId, Size,VirtualDiskFootPrint).

Go to the Server manager - Storage Pools

Remove the retired disk.

Increase virtual disk size.

Increase disk size in the Disk Management

Remove the retired disk in the Disk Management

Detach the retired disk in Azure Portal

Delete the retired disk.

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How to increase disk size on a Azure SQL VM server?

2 answers

Your answer