Convert your OS disks to Standard SSD or Premium SSD before 8 September 2028

Hello @Idit Bnaya

Thank you for reaching out with this question. I understand the concern, especially given the upcoming retirement of Standard HDD as OS disks by 8 September 2028 and the scale of your Azure Site Recovery (ASR) deployment.

For clarity:

At this time, Azure does not provide a supported PowerShell or Azure CLI method to bulk‑change the disk type of ASR replica disks (RecoveryReplicaDiskId) for machines that are already protected. The supported guidance only allows disk‑type changes to ASR replica disks through manual actions in the Azure portal, performed per disk. There is no documented API, CLI, or automation workflow that can update ASR replica disk SKUs in bulk without re‑protection.

Microsoft documentation does confirm that disk types can be changed after protection, but this applies to individual managed disks via the portal, not large‑scale automated updates.

For large environments, Microsoft recommends focusing on the source VM OS disks, which does support bulk identification and conversion:

1. Identify all OS disks currently using Standard HDD using PowerShell or Azure CLI
2. Convert source OS disks to Standard SSD or Premium SSD using supported tooling
3. Ensure all new ASR protections inherit the updated disk type

Example commands to identify affected OS disks:

Get-AzDisk | Where-Object { $_.Sku.Name -eq "Standard_LRS" -and $_.OsType }

az disk list --query "[?sku.name=='Standard_LRS' && osType!=null]" --output table

1.Bulk conversion is supported for source VM OS disks

2.Bulk conversion is not supported for existing ASR replica disks

Links :
https://dori-uw-1.kuma-moon.com/en-us/azure/virtual-machines/disks-hdd-os-retirement
https://dori-uw-1.kuma-moon.com/en-us/azure/virtual-machines/disks-convert-types?tabs=azure-powershell

Thanks,
Manish.

There is no documented or supported bulk PowerShell/CLI method in the provided content to change Azure Site Recovery RecoveryReplicaDiskId disk types in-place for protected VMs.

The available guidance covers:

• Identifying all OS disks of a given storage type (for example, Standard HDD LRS) at scale using Azure PowerShell or Azure CLI:
  • PowerShell example for a subscription:

        Get-AzDisk | Where-Object { $_.Sku.Name -eq "Standard_LRS" -and $_.OsType }
    

  • CLI example for a subscription:

        az disk list --query "[?sku.name=='Standard_LRS' && osType!=null]" --output table
    

• Converting managed disk types (Standard HDD ↔ Standard SSD ↔ Premium SSD) for individual disks or all disks of a VM using Portal, PowerShell, or CLI, with the requirement that the VM be stopped and that only managed disks are supported.
• The retirement notice for Standard HDD OS disks (not specifically ASR replica disks) and the recommendation to convert OS disks to Standard SSD or Premium SSD before 8 September 2028.

However, none of the referenced documentation describes:

• A PowerShell/CLI operation that targets ASR replica resources (such as RecoveryReplicaDiskId) directly, or
• A supported bulk workflow to change the disk type of ASR replica disks without re-protecting the VMs.

Based on the provided content, only standard managed disk conversion methods are documented and these apply to regular VM disks, not explicitly to ASR replica disks. For ASR-specific behavior and any supported bulk approach to changing RecoveryReplicaDiskId disk types without reprotection, the documented path is to contact support.

References:

• Migrate your Standard HDD OS disks by September 08, 2028
• Convert the disk type of an Azure managed disk
• Tutorial: Manage disks with Azure PowerShell
• Azure managed disk types
• Tutorial: Create and use disks with Virtual Machine Scale Set with Azure PowerShell