Offline Initialize

To enable update, Trident requires some state related to how an existing operating system is laid out on disk.

For a bare metal installation, this state is generated by Trident during Clean Install when a servicing ISO calls trident install to deploy a COSI file.

In contrast, virtual machines are typically created from a virtual disk containing the operating system, trident install is never invoked. Offline Initialize has been created to generate the state that Trident requires to service the virtual machine.

To utilize Offline Initialize, add the trident package and invoke trident offline-initialize as part of your Image Customizer configuration:

os:
  packages:
    install:
      - trident

scripts:
  postCustomization:
    - content: |
        trident offline-initialize

When Offline Initialize is executed, it will read the Image Customizer history file, understand the disk layout, and generate the necessary state for Trident to service the eventual virtual machine.