Docker – Why Does a CentOS Docker Container Identify as Ubuntu

This is related to a new driver introduced in Fedora 20 that does not need more than those two governors. See this thread CPU Governors - where is ONDEMAND? for details.

To have the missing governors, you should boot with the kernel parameter intel_pstate=disable.

To do so, in the GRUB boot screen, choose "edit boot commandline" and add this to the line which starts with kernel. You can also add it permanently to the grub config file.

Note that normally you should not need others governors than those proposed by the new driver which does its job perfectly.

If you run a container..

eg

docker run alpine echo hello

It looks like it cleans up afterwards...

% docker ps
CONTAINER ID        IMAGE               COMMAND             CREATED             STATUS              PORTS               NAMES

But it doesn't it's still there.

% docker ps -a
CONTAINER ID        IMAGE               COMMAND             CREATED             STATUS                      PORTS               NAMES
3a4772c0f165        alpine              "echo hello"        22 seconds ago      Exited (0) 20 seconds ago                       relaxed_ramanujan

This can be cleaned up with the rm command

% docker container rm 3a4772c0f165 
3a4772c0f165

% docker ps -a
CONTAINER ID        IMAGE               COMMAND             CREATED             STATUS              PORTS               NAMES

So:

• docker kill will kill a container.
• docker rm will clean up a terminated container.

They are different things.

Note: you can tell containers to auto-clean:

% docker run --rm alpine echo hello
hello

% docker ps -a
CONTAINER ID        IMAGE               COMMAND             CREATED             STATUS              PORTS               NAMES

Then you don't need to manually rm.