On 18.02.2023 19:10, Bill Merriam wrote:

Long ago I started running VM's with XEN. At that time each VM (I think) used its own copy of the kernel and related resources. I could only run a few VM's before I ran out of RAM. Because of that I ran lots of services in the same VM.

Enter KVM, then my VM's shared a kernel

You are mistaken (unless you run user mode Linux which is only loosely related to KVM).

and my RAM requirements fell. Now I run only one major service (DNS, database, etc) in each VM.

Now along comes Podman and containers. If I move to running each service in its only container what does that do to my RAM (and CPU) requirements. How many copies of the kernel and its resource will I be running?

You have one kernel on your host. Containers do not run separate kernels. It is unclear what "resource" you mean.

I think maybe I can use the host's kernel in a container or use a different one.

You cannot use "different one".

I am less concerned about disk space usage, but can I share some part of the root file system between containers?

This is entirely up to the container. When you are running Debian on openSUSE you do not share any user space binaries.

Can someone tell me where to find a discussion of this??

Internet?

Thanks.

Bill