You have a workload running on Compute Engine that is critical to your business. You want to ensure that the data on the boot disk of this workload…

Creating a snapshot schedule is the official, Google-recommended method for automating backups of Compute Engine persistent disks. This managed service directly addresses all the requirements: it can be configured to create snapshots at regular intervals, it includes a retention policy to automatically delete older backups to control costs, and snapshots provide the fastest method for restoring a disk's data. This approach is more robust, manageable, and less error-prone than custom scripting solutions.

A. An instance template is a blueprint for creating new virtual machine instances; it does not back up the data of an existing, running workload.

C. Using a cron job with gcloud is a manual, self-managed solution that lacks the built-in retention policies and reliability of the managed snapshot schedule service.

D. Exporting an image to Cloud Storage is a valid backup method, but restoring from it is a multi-step process (import image, then create disk) which is slower than creating a disk directly from a snapshot.

1. Google Cloud Documentation - Create scheduled snapshots for persistent disk: "To back up your persistent disks

Google Cloud recommends that you set up a snapshot schedule. A snapshot schedule is a resource that defines the frequency of snapshot creation

a retention policy

and a location for the snapshots." This page details the creation and management of schedules

including the retention policy for automatic cleanup.

2. Google Cloud Documentation - About disk snapshots: "Use snapshots to back up data from your persistent disks. ... You can use a snapshot to create a new disk that contains the data from the snapshot." This confirms snapshots are the primary backup mechanism and can be used for quick restoration.

3. Google Cloud Documentation - Best practices for Compute Engine disk snapshots: "Automate your snapshot creation process by using snapshot schedules. This is the best practice for backing up your Compute Engine workloads." This explicitly states that using snapshot schedules is the recommended best practice.