Maintenance control for OS image upgrades on Azure Virtual Machine Scale Sets using Azure CLI

Maintenance control lets you decide when to apply automatic guest OS image upgrades to your Virtual Machine Scale Sets. This topic covers the Azure CLI options for Maintenance control. For more information on using Maintenance control, see Maintenance control for Azure Virtual Machine Scale Sets.

Create a maintenance configuration

Use az maintenance configuration create to create a maintenance configuration. This example creates a maintenance configuration named myConfig scoped to the osimage.

az group create \
   --location chinaeast \
   --name myMaintenanceRG
az maintenance configuration create \
   -g myMaintenanceRG \
   --resource-name myConfig \
   --maintenance-scope osimage\
   --location chinaeast

Copy the configuration ID from the output to use later.

Using --maintenance-scope osimage ensures that the maintenance configuration is used for controlling updates to the guest OS.

If you try to create a configuration with the same name, but in a different location, you will get an error. Configuration names must be unique to your resource group.

You can query for available maintenance configurations using az maintenance configuration list.

az maintenance configuration list --query "[].{Name:name, ID:id}" -o table 

Create a maintenance configuration with a scheduled window

You can also declare a scheduled window when Azure will apply the updates on your resources. This example creates a maintenance configuration named myConfig with a scheduled window of 5 hours on the fourth Monday of every month. Once you create a scheduled window, you no longer have to apply the updates manually.

az maintenance configuration create \
   -g myMaintenanceRG \
   --resource-name myConfig \
   --maintenance-scope osimage \
   --location chinaeast \
   --maintenance-window-duration "05:00" \
   --maintenance-window-recur-every "Day" \
   --maintenance-window-start-date-time "2020-12-30 08:00" \
   --maintenance-window-time-zone "Pacific Standard Time"

Assign the configuration

Use az maintenance assignment create to assign the configuration to your Virtual Machine Scale Set.

Enable automatic OS upgrade

You can enable automatic OS upgrades for each Virtual Machine Scale Set that is going to use maintenance control. For more information about enabling automatic OS upgrades on your Virtual Machine Scale Set, see Azure Virtual Machine Scale Set automatic OS image upgrades.

Next steps