Convert a disk from LRS to ZRS

Article
09/02/2024

This article explains how to convert an existing disk from locally redundant storage (LRS) to zone-redundant storage (ZRS).

For conceptual information on ZRS, see Zone-redundant storage for managed disks

Limitations

ZRS for managed disks is only supported with Premium SSD and Standard SSD managed disks. ZRS for managed disks isn't supported with Premium SSD v2 managed disks. Force detach only supports data disks.

Regional availability

ZRS disks are currently available in China North 3.

Determine infrastructure redundancy

Before you convert a disk from LRS to ZRS, you must first identify whether the disk is zonal or regional. How you migrate your disk changes based on whether it's zonal or regional.

Sign in to the Azure portal
Navigate to your disk and look under Availability zone on the Overview tab.
1. If the value is No infrastructure redundancy required you have a regional disk. Use Regional migration to migrate your disk.
2. If the value is anything else, you have a zonal disk. Use Zonal migration to migrate your disk.

Run the following command and observe the output. If there's no value in Zones, you have a regional disk. Use Regional migration to migrate your disk. Otherwise, you have a zonal disk. Use Zonal migration to migrate your disk.

Get-AzDisk -DiskName your_disk_name_here -ResourceGroupName your_RG_name_here

Run the following command and observe the output. If there's no value in zones you have a regional disk. Use Regional migration to migrate your disk. Otherwise, you have a zonal disk. Use Zonal migration to migrate your disk.

az disk show --name your_disk_name_here --resource-group your_RG_name_here

Regional migration

You can directly change the disk type of regional disks with the following options.

Follow these steps:

Sign in to the Azure portal.
Select the VM from the list of Virtual machines.
If the VM isn't stopped, select Stop at the top of the VM Overview pane, and wait for the VM to stop.
In the pane for the VM, select Disks from the menu.
Select the disk that you want to convert.
Select Size + performance from the menu.
Change the Account type from the original disk type to the desired disk type.
Select Save, and close the disk pane.

The disk type conversion is instantaneous. You can start your VM after the conversion.


$diskName = 'yourDiskName'
# resource group that contains the managed disk
$rgName = 'yourResourceGroupName'
# Choose between StandardSSD_ZRS or Premium_ZRS based on your scenario
$storageType = 'Premium_ZRS'
# Premium capable size 
$size = 'Standard_DS2_v2'

$disk = Get-AzDisk -DiskName $diskName -ResourceGroupName $rgName

# Get parent VM resource
$vmResource = Get-AzResource -ResourceId $disk.ManagedBy

# Stop and deallocate the VM before changing the storage type
Stop-AzVM -ResourceGroupName $vmResource.ResourceGroupName -Name $vmResource.Name -Force

$vm = Get-AzVM -ResourceGroupName $vmResource.ResourceGroupName -Name $vmResource.Name 

# Change the VM size to a size that supports Premium storage
# Skip this step if converting storage from Premium to Standard
$vm.HardwareProfile.VmSize = $size
Update-AzVM -VM $vm -ResourceGroupName $rgName

# Update the storage type
$disk.Sku = [Microsoft.Azure.Management.Compute.Models.DiskSku]::new($storageType)
$disk | Update-AzDisk

Start-AzVM -ResourceGroupName $vm.ResourceGroupName -Name $vm.Name


#resource group that contains the managed disk
$rgName='yourResourceGroup'

#Name of your managed disk
diskName='yourManagedDiskName'

#Premium capable size 
#Required only if converting from Standard to Premium
size='Standard_DS2_v2'

#Choose between StandardSSD_ZRS or Premium_ZRS based on your scenario
sku='Premium_ZRS'

#Get the parent VM Id 
vmId=$(az disk show --name $diskName --resource-group $rgName --query managedBy --output tsv)

#Deallocate the VM before changing the size of the VM
az vm deallocate --ids $vmId 

#Change the VM size to a size that supports Premium storage 
#Skip this step if converting storage from Premium to Standard
az vm resize --ids $vmId --size $size

# Update the SKU
az disk update --sku $sku --name $diskName --resource-group $rgName 

az vm start --ids $vmId

Zonal migration

In this section, you migrate the data from your current managed disks to ZRS managed disks.

If you have a zonal disk, you can't directly change its type. You must take a snapshot and use that snapshot to create a new ZRS disk.

Step 1: Create your snapshot

The easiest and cleanest way to create a snapshot is to take one while the VM is offline. See Snapshots. If you choose this approach, some downtime should be expected. To create a snapshot of your VM using the Azure portal, PowerShell, or Azure CLI, see Create a snapshot of a virtual hard disk

If you're taking a snapshot of a disk that's attached to a running VM, read the guidance in Snapshots before continuing.

Note

The source managed disks remain intact with their current configurations and you'll continue to be billed for them. To avoid this, you must manually delete the disks once you've finished your migration and confirmed the new disks are working. For more information, see Find and delete unattached Azure managed and unmanaged disks.

Step 2: Migrate the data on your managed disks

Now that you have snapshots of your original disks, you can use them to create ZRS managed disks.

Migrate your data to ZRS managed disks

Create a ZRS managed disk from the source disk snapshot by using the following Azure CLI snippet:

# Create a new ZRS Managed Disks using the snapshot Id and the SKU supported   
storageType=Premium_ZRS 
location=chinanorth3

az disk create --resource-group $resourceGroupName --name $diskName --sku $storageType --size-gb $diskSize --source $snapshotId

Step 3: Create a new VM with your new disks

Now that you have migrated your data to ZRS managed disks or zonal managed disks, create a new VM with these new disks set as the OS and data disks:


    az vm create -g MyResourceGroup -n MyVm --attach-os-disk newZonalOSDiskCopy --attach-data-disks newZonalDataDiskCopy --os-type linux