diff --git a/azurerm/internal/services/compute/linux_virtual_machine_resource.go b/azurerm/internal/services/compute/linux_virtual_machine_resource.go
index 14b122fb0424a..d9d2d62fbe4c7 100644
--- a/azurerm/internal/services/compute/linux_virtual_machine_resource.go
+++ b/azurerm/internal/services/compute/linux_virtual_machine_resource.go
@@ -642,7 +642,7 @@ func resourceLinuxVirtualMachineUpdate(d *schema.ResourceData, meta interface{})
 		return fmt.Errorf("Error retrieving InstanceView for Linux Virtual Machine %q (Resource Group %q): %+v", id.Name, id.ResourceGroup, err)
 	}
 
-	shouldTurnBackOn := shouldBootVirtualMachine(instanceView)
+	shouldTurnBackOn := virtualMachineShouldBeStarted(instanceView)
 	hasEphemeralOSDisk := false
 	if props := existing.VirtualMachineProperties; props != nil {
 		if storage := props.StorageProfile; storage != nil {
diff --git a/azurerm/internal/services/compute/virtual_machine.go b/azurerm/internal/services/compute/virtual_machine.go
index 2dafe26345ac4..80e008595f834 100644
--- a/azurerm/internal/services/compute/virtual_machine.go
+++ b/azurerm/internal/services/compute/virtual_machine.go
@@ -292,7 +292,7 @@ func virtualMachineOSDiskSchema() *schema.Schema {
 					Type:         schema.TypeInt,
 					Optional:     true,
 					Computed:     true,
-					ValidateFunc: validation.IntBetween(0, 1023),
+					ValidateFunc: validation.IntBetween(0, 2048),
 				},
 
 				"name": {
diff --git a/azurerm/internal/services/compute/virtual_machine_instance.go b/azurerm/internal/services/compute/virtual_machine_instance.go
index 087186e201997..fdd11cf97e8c8 100644
--- a/azurerm/internal/services/compute/virtual_machine_instance.go
+++ b/azurerm/internal/services/compute/virtual_machine_instance.go
@@ -6,11 +6,11 @@ import (
 	"github.com/Azure/azure-sdk-for-go/services/compute/mgmt/2019-07-01/compute"
 )
 
-// shouldBootVirtualMachine determines if the Virtual Machine should be started after
+// virtualMachineShouldBeStarted determines if the Virtual Machine should be started after
 // the Virtual Machine has been shut down for maintenance. This means that Virtual Machines
 // which are already stopped can be updated but will not be started
 // nolint: deadcode unused
-func shouldBootVirtualMachine(instanceView compute.VirtualMachineInstanceView) bool {
+func virtualMachineShouldBeStarted(instanceView compute.VirtualMachineInstanceView) bool {
 	if instanceView.Statuses != nil {
 		for _, status := range *instanceView.Statuses {
 			if status.Code == nil {
@@ -24,11 +24,7 @@ func shouldBootVirtualMachine(instanceView compute.VirtualMachineInstanceView) b
 			}
 
 			state = strings.TrimPrefix(state, "powerstate/")
-			switch strings.ToLower(state) {
-			case "deallocating":
-			case "deallocated":
-			case "stopped":
-			case "stopping":
+			if strings.EqualFold(state, "running") {
 				return true
 			}
 		}
diff --git a/azurerm/internal/services/compute/virtual_machine_scale_set.go b/azurerm/internal/services/compute/virtual_machine_scale_set.go
index 17c8fda1b9ef6..385a7c7333228 100644
--- a/azurerm/internal/services/compute/virtual_machine_scale_set.go
+++ b/azurerm/internal/services/compute/virtual_machine_scale_set.go
@@ -937,7 +937,7 @@ func VirtualMachineScaleSetOSDiskSchema() *schema.Schema {
 					Type:         schema.TypeInt,
 					Optional:     true,
 					Computed:     true,
-					ValidateFunc: validation.IntBetween(0, 1023),
+					ValidateFunc: validation.IntBetween(0, 2048),
 				},
 
 				"write_accelerator_enabled": {
diff --git a/azurerm/internal/services/compute/windows_virtual_machine_resource.go b/azurerm/internal/services/compute/windows_virtual_machine_resource.go
index 0955a7bea4834..b32bd39c1c3b4 100644
--- a/azurerm/internal/services/compute/windows_virtual_machine_resource.go
+++ b/azurerm/internal/services/compute/windows_virtual_machine_resource.go
@@ -667,7 +667,7 @@ func resourceWindowsVirtualMachineUpdate(d *schema.ResourceData, meta interface{
 		return fmt.Errorf("Error retrieving InstanceView for Windows Virtual Machine %q (Resource Group %q): %+v", id.Name, id.ResourceGroup, err)
 	}
 
-	shouldTurnBackOn := shouldBootVirtualMachine(instanceView)
+	shouldTurnBackOn := virtualMachineShouldBeStarted(instanceView)
 	hasEphemeralOSDisk := false
 	if props := existing.VirtualMachineProperties; props != nil {
 		if storage := props.StorageProfile; storage != nil {