You may wonder why the Windows Container starts up so slowly. Because you never pinned your exact base image version of your container image. In this article, I’ll explain what was going on under the hood and how you can handle it correctly.
Microsoft regularly publishes newer Windows Server container images when they roll out the more recent Windows Server security patches and hotfixes. For example, when Microsoft releases KB4598242 for 20H2, the container base image also released.
When the new base image rolled out to the mcr.microsoft.com, the new image consisted of two parts. The first part is the base image of the Windows Server container, which will never change. And the moving part is the latter part, which includes the hotfix.