Creating and Viewing Images in Google Cloud Platform
Why is Creating and Viewing Images Important?
Creating and viewing images is a fundamental skill for managing compute resources in Google Cloud Platform. Images serve as templates for creating new virtual machine instances, enabling you to capture the state of a disk including the operating system, applications, and configurations. This capability is essential for disaster recovery, scaling applications, and maintaining consistent environments across your infrastructure.
What are Images in GCP?
An image in GCP is a bundle that contains the operating system, boot loader, file system structure, and any pre-installed software. There are several types of images:
- Public Images: Provided by Google or third-party vendors, including various Linux distributions and Windows Server versions
- Custom Images: Created by you from existing disks, snapshots, images, or imported from other sources
- Machine Images: Store all configuration, metadata, permissions, and data from one or more disks attached to a VM instance
How Creating and Viewing Images Works
Creating Images:
You can create custom images using the following methods:
1. From a disk: Create an image from a persistent disk attached to a stopped VM
2. From a snapshot: Create an image from an existing snapshot
3. From another image: Create a new image based on an existing image
4. From Cloud Storage: Import a virtual disk file stored in a bucket
Using gcloud CLI:
gcloud compute images create IMAGE_NAME --source-disk SOURCE_DISK --source-disk-zone ZONE
Using Console: Navigate to Compute Engine > Images > Create Image
Viewing Images:
To view available images:
- Console: Go to Compute Engine > Images to see custom images, or select Public Images tab
- gcloud CLI: Use gcloud compute images list to view all images or gcloud compute images describe IMAGE_NAME for details
Image Families
Image families group related images together and always point to the newest, non-deprecated image in that family. This ensures that new VMs always use the most recent version of an image.
Best Practices
- Stop the VM before creating an image to ensure data consistency
- Use image families to manage versioning
- Deprecate old images rather than deleting them
- Store images in multi-regional locations for better availability
- Use labels to organize and track images
Exam Tips: Answering Questions on Creating and Viewing Images
1. Know the difference between images, snapshots, and machine images: Images are used for creating new instances, snapshots are incremental backups of disks, and machine images capture complete VM configurations
2. Remember source options: Images can be created from disks, snapshots, other images, or imported from Cloud Storage
3. Understand image families: Questions may ask about maintaining consistent deployments using image families
4. Know the commands: Be familiar with gcloud compute images create, list, describe, and delete
5. Deprecation vs Deletion: Deprecating an image marks it as outdated but keeps it available; deletion removes it permanently
6. Permissions: Creating images requires the compute.images.create permission, typically included in the Compute Admin role
7. Cross-project sharing: Images can be shared across projects by granting appropriate IAM permissions
8. Scenario-based questions: When asked about deploying consistent environments or disaster recovery, custom images are often the correct solution