What images need to be re-built when which parts of the conf/config.yml are modified?

[SvenDowideit]

I see mention of running build.sh -S if the profiles are changed, but would like to know what needs doing if other parts of the file are changed.

And similarly, assuming that my build system is separate from my run time system, what non-image things need to be transferred - there's a lot of run time volumes, but its not entirely clear if they're just cache / run time data.

[brod-intel]

./build.sh -S simply skips building ESP container services which have nothing to do with profile builds. The ESP containers only need to built be initially and when there is a new release of ESP repo.

./build.sh -S also means it will loop through conf/config.yml and sync all profiles then check profiles with "build" scripts. These build scripts perform pre-build process specifically. You use this feature if you want build a custom kernel, use debmirror to clone a distro on ESP, build source tarbal;s etc.