Pause Blender terminal command:
<i>killall -s STOP blender</i>
Resume Blender terminal command:
<i>killall -s CONT blender</i>
You can do launchers with this commands, like a Pause and Resume buttons, or shell or bat script ,or type it in to the terminal.
When you pause a render job (cycles, Blender render) with Blender GUI/Interface/program started, Blender become a dead brick. You can’t do anything in blender. After a while you have a program list with a screenshot of your desktop. When you resume the render, or preview render, Blender gets the life back and the render continue. Test for your self so you don’t get scared. (also working with blender command line render)