Important
For standby pools to successfully create and manage resources, it requires access to the associated resources in your subscription. Ensure the correct permissions are assigned to the standby pool resource provider in order for your standby pool to function properly. For detailed instructions, see configure role permissions for standby pools.
You can update the state of the instances and the max ready capacity of your standby pool at any time. The standby pool name can only be set during standby pool creation. If updating the provisioning state to hibernated, ensure that the scale set is properly configured to use hibernated VMs. For more information see, Hibernation overview.
When changing the provisioning state of your standby pool, transitioning between the following states below are supported. Transitioning between a Stopped (deallocated) state and a hibernated state is not supported. If using a Stopped (deallocated) pool and you want to instead use a hibernated pool, first transition to a running pool then update the provisioning state to hibernated.
| Initial state |
Updated state |
| Running |
Stopped (deallocated) |
| Running |
Hibernated |
| Stopped (deallocated) |
Running |
| Hibernated |
Running |
| Hibernated |
Stopped (deallocated) |
Update a standby pool
Note
Setting the standby pool VM state to hibernated is not yet available in the Azure portal. To configure a standby pool with a hibernated VM state use an alternative SDK such as CLI or PowerShell.
- Navigate to Virtual Machine Scale set the standby pool is associated with.
- Under Availability + scale select Standby pool.
- Select Manage pool.
- Update the configuration and save any changes.
Update an existing standby pool using az standby-vm-pool update.
az standby-vm-pool update \
--resource-group myResourceGroup \
--name myStandbyPool \
--max-ready-capacity 20 \
--min-ready-capacity 5 \
--vm-state "Deallocated"
Update an existing standby pool using Update-AzStandbyVMPool.
Update-AzStandbyVMPool `
-ResourceGroup myResourceGroup `
-Name myStandbyPool `
-MaxReadyCapacity 20 `
-MinReadyCapacity 5 `
-VMState "Deallocated"
Update an existing standby pool deployment. Deploy the updated template using az deployment group create or New-AzResourceGroupDeployment.
{
"$schema": "https://schema.management.azure.com/schemas/2019-04-01/deploymentTemplate.json#",
"contentVersion": "1.0.0.0",
"parameters": {
"___location": {
"type": "string",
"defaultValue": "east us"
},
"name": {
"type": "string",
"defaultValue": "myStandbyPool"
},
"maxReadyCapacity" : {
"type": "int",
"defaultValue": 10
},
"minReadyCapacity" : {
"type": "int",
"defaultValue": 5
},
"virtualMachineState" : {
"type": "string",
"defaultValue": "Deallocated"
},
"attachedVirtualMachineScaleSetId" : {
"type": "string",
"defaultValue": "/subscriptions/{subscriptionID}/resourceGroups/myResourceGroup/providers/Microsoft.Compute/virtualMachineScaleSets/myScaleSet"
}
},
"resources": [
{
"type": "Microsoft.StandbyPool/standbyVirtualMachinePools",
"apiVersion": "2025-03-01",
"name": "[parameters('name')]",
"___location": "[parameters('___location')]",
"properties": {
"elasticityProfile": {
"maxReadyCapacity": "[parameters('maxReadyCapacity')]",
"minReadyCapacity": "[parameters('minReadyCapacity')]"
},
"virtualMachineState": "[parameters('virtualMachineState')]",
"attachedVirtualMachineScaleSetId": "[parameters('attachedVirtualMachineScaleSetId')]"
}
}
]
}
Update an existing standby pool deployment. Deploy the updated template using az deployment group create or New-AzResourceGroupDeployment.
param ___location string = resourceGroup().___location
param standbyPoolName string = 'myStandbyPool'
param maxReadyCapacity int = 10
param minReadyCapacity int = 5
@allowed([
'Running'
'Deallocated'
'Hibernated'
])
param vmState string = 'Deallocated'
param virtualMachineScaleSetId string = '/subscriptions/{subscriptionID}/resourceGroups/myResourceGroup/providers/Microsoft.Compute/virtualMachineScaleSets/myScaleSet'
resource standbyPool 'Microsoft.standbypool/standbyvirtualmachinepools@2025-03-01' = {
name: standbyPoolName
___location: ___location
properties: {
elasticityProfile: {
maxReadyCapacity: maxReadyCapacity
minReadyCapacity: minReadyCapacity
}
virtualMachineState: vmState
attachedVirtualMachineScaleSetId: virtualMachineScaleSetId
}
}
Update an existing standby pool using Create or Update.
PUT https://management.azure.com/subscriptions/{subscriptionID}/resourceGroups/myResourceGroup/providers/Microsoft.StandbyPool/standbyVirtualMachinePools/myStandbyPool?api-version=2025-03-01
{
"type": "Microsoft.StandbyPool/standbyVirtualMachinePools",
"name": "myStandbyPool",
"___location": "east us",
"properties": {
"elasticityProfile": {
"maxReadyCapacity": 20
"minReadyCapacity": 5
},
"virtualMachineState":"Deallocated",
"attachedVirtualMachineScaleSetId": "/subscriptions/{subscriptionID}/resourceGroups/myResourceGroup/providers/Microsoft.Compute/virtualMachineScaleSets/myScaleSet"
}
}
Delete a standby pool
- Navigate to Virtual Machine Scale set the standby pool is associated with.
- Under Availability + scale select Standby pool.
- Select Delete pool.
- Select Delete.
Delete an existing standby pool using az standbypool delete.
az standby-vm-pool delete \
--resource-group myResourceGroup \
--name myStandbyPool
Delete an existing standby pool using Remove-AzStandbyVMPool.
Remove-AzStandbyVMPool `
-ResourceGroup myResourceGroup `
-Name myStandbyPool `
-Nowait
Delete an existing standby pool using Delete.
DELETE https://management.azure.com/subscriptions/{subscriptionID}/resourceGroups/myResourceGroup/providers/Microsoft.StandbyPool/standbyVirtualMachinePools/myStandbyPool?api-version=2025-03-01
Next steps
Review the most frequently asked questions about standby pools for Virtual Machine Scale Sets.