What is a VM Image in Azure?
A VM image in Azure is a copy of a full Azure virtual machine, including both the operating system (OS) disk and data disks. It can be used to create new virtual machines that are identical to the source VM.
To build a golden image, you can first build and customize a virtual machine, and then save the image as a VHD file. Point to be noted, as of now Azure only supports VHD files to create virtual machines from golden images.
Where can we save images in Azure?
You can save custom images in the Azure compute gallery. The compute gallery is a repository for storing and managing virtual machine images. It allows you to share images with other users and organizations, and to deploy images across multiple Azure regions.
What are the uses of VM images in Azure?
VM images can be shared with other users and organizations and can be used to create new virtual machines of the same size and configuration as the source VM. It can also be used to deploy virtual machines across multiple Azure regions.
What are VM Image Types in Azure?
There are two types of VM images in Azure: specialized and generalized.
1. Specialized VM Images
A specialized VM image is a copy of a live virtual machine (VM). It includes the pre-configured operating system, software, user accounts, databases, connection information, and other data for your system. Specialized VM images can be used as a backup of your system at a particular point in time, or you can use them to create new VMs that have the same configuration as the original VM.
Some examples of specialized VM images in Azure include:
- Azure Arc-enabled servers: These images allow you to manage servers on-premises, in multi-cloud, and at the edge.
- Azure Stack Hub: These images allow you to run Azure services on-premises.
- Azure Security Center: These images include pre-configured security settings and tools to help protect your VMs and applications.
- Azure DevOps: These images include pre-configured tools and settings for DevOps, such as Visual Studio, Git, and Azure Pipelines.
- Azure SQL Database: These images are specialized for running SQL Database on Azure.
- Azure Machine Learning: These images are specialized for running machine learning models on Azure.
- Azure IoT Edge: These images are specialized for running IoT Edge on Azure.
2. Generalized VM Images
A generalized VM image is a VM image that has had all of its unique identifying information removed. This means that the original VM is unusable after it has been generalized. Generalized VM images are typically used to create new VMs that will be used in a shared environment, such as a cloud service.
To generalize a VM, you can use the Microsoft System Preparation (Sysprep) tool for Windows VMs or the Windows Azure Linux Agent (waagent) for Linux VMs.