Welcome to Preparing for the Associate Cloud Engineering Exam. This module will cover some concepts necessary for ensuring successful operation of a Cloud solution. This module is all about managing your Cloud resources, whether it's Compute Engine, Kubernetes Engine, App Engine, data solutions, network resources, or logging, and monitoring. Our first step on this particular part of the journey as managing Compute Engine Resources. Section 4.1 covers quite a lot of tasks needed to manage Compute Engine instances, as you can see. We won't have time in this course to go over all the tasks in this list, but let's begin by reviewing VM images in a very general way. You can use operating system images to create boot disks for your VM instances. You can use one of the following image types. Public images are provided and maintained by Google, open-source communities, and third-party vendors. By default, all projects have access to these images, and can use them to create instances. Custom images are available only to your project. You can create a custom image from boot disks and other images. Then use the custom image grid and instance. You can use most public images at no additional cost, but there are some premium images that do add additional cost to your instances. Custom images that you import to Compute Engine at no cost to your instances, but do incur an image storage charge, or you keep your custom image in your project. Some images are capable of running containers on Compute Engine. Support for Compute Engine provided public OS images are subject to the life cycle of the respective OS. Snapshots are incremental and automatically compressed, so you can create regular snapshots on a persistent disk faster in a much lower cost, than if you regularly created a full image of the disk. Incremental snapshots work in the following manner. The first successful snapshot of a persistent disk is a full snapshot that contains all the data on a persistent disk. The second snapshot only contains any new data or modify data since the first snapshot. They that hasn't changed since snapshot 1 isn't included. Instead snapshot 2 contains references to snapshot 1 for any unchanged data. Snapshot 3 contains any new, or changing it since snapshot 2, but won't contain any unchanged data from snapshot 1 or 2. Instead, snapshot 3 contains references to blocks and snapshot 1 and snapshot 2 for any unchanged data. This repeats for all subsequent snapshots of the persistent disk. Snapshots are always created based on the last successful snapshot taken. Compute Engine stores multiple copies of each snapshot across multiple locations with automatic checksums to ensure the integrity of your data. Use IAM roles to share snapshots across project. To see lists of snapshots available to a project, use the gcloud compute snapshots list command. To list information about a particular snapshot, such as the creation time, size, and source disc, use the gcloud compute snapshots describe command. A custom image is the boot disk image that you own and control access to. If you regularly update your custom images with newer configurations in software, you can group those images into an image family. The image family always points to the most recent image in that family, so your instance templates and scripts can use that image without having to update references to a specific image version. You can create disk images from the following sources: a persistent disk, even while that this is attached to an instance; a snapshot of a persistent disk; another image in your project; an image that is shared from another project, or compressed RAW image in Google Cloud Storage.
