Study Google Cloud ACE VM Operations: key concepts, common traps, and exam decision cues.
This lesson covers the basic Compute Engine operations ACE expects: knowing what is running, connecting safely, and preserving or reusing VM state through snapshots and images.
Snapshot: Point-in-time copy of a disk used for backup, recovery, or later reuse.
Image: Reusable VM boot template derived from an existing disk or snapshot.
This ACE topic is about operator judgment. Google Cloud wants to see whether you can:
| Need | Strongest first lane | Why it fits |
|---|---|---|
| See what VMs exist, what zone they run in, and whether they are healthy | Compute Engine inventory views or gcloud compute instances list |
This is instance inventory, not logging or DNS |
| Connect to Linux VMs using Google-managed identity controls | OS Login | Centralized access control instead of loose SSH key sprawl |
| Preserve disk state before risky change or for backup recovery | Snapshot | Disk recovery copy |
| Create many new VMs from a known base build | Image | Reusable bootable template |
| Inspect and manage patching or VM fleet posture | VM Manager | Operational management layer across VMs |
OS Login: Google Cloud feature that ties VM SSH access to IAM identities instead of unmanaged per-instance SSH keys.
VM Manager: Fleet operations capability for patching, inventory, and VM management tasks.
| If the question emphasizes | Strongest first lane | Why |
|---|---|---|
| backup, point-in-time recovery, restore after failure | Snapshot | The goal is preserving disk state |
| standard base machine, repeatable instance creation, reusable boot disk source | Image | The goal is template reuse |
| both recovery and later template creation | Snapshot first, then image if needed | Recovery copy and reusable golden image are different tasks |
ACE questions often test whether you jump to the right operational step before changing anything.
| Situation | Strongest first move |
|---|---|
| “The VM is running but nobody knows where or how it is configured.” | Check Compute Engine inventory, instance details, and metadata first |
| “Engineers need controlled SSH access through identities.” | Prefer OS Login |
| “We are about to patch or reconfigure the disk and want a rollback point.” | Take a snapshot first |
| “We want a standard base image for future instances.” | Create or use an image |
| Trap | Better reading |
|---|---|
| “Snapshot and image are interchangeable.” | Snapshot is recovery-oriented; image is template-oriented. |
| “SSH access always means manual key distribution.” | ACE often expects OS Login when identity-managed access is the goal. |
| “Inventory is just a logging problem.” | Inventory starts with the Compute Engine resource view, then logs if the issue is behavioral. |
| “If one VM works, cloning it always starts with a snapshot.” | If the real goal is repeatable provisioning, think image. |
An operations team is about to upgrade packages on a production Linux VM. They want the fastest rollback path if the instance becomes unusable, and they also plan to create a standardized base machine later for future instances.
The strongest first move is:
Correct answer: 2. The immediate need is rollback and recovery, which points to a snapshot. A reusable image is a separate later concern.