Ok here is where we find the problems tb.sh create .... ok tb,sh exec ..... ok so reading this i think slim clarification is needed, do we run centos-mirror-tools/download_mirror.sh outside the container? Package mirror creation Once the StarlingX docker image has been built, you must create a mirror before creating the ISO image. Basically, a mirror is a directory that contains a series of packages. The packages are organized to be consumed by the ISO creation scripts. The HOST_MIRROR_DIR variable provides the path to the mirror. The buildrc file sets the value of this variable unless the localrc file has modified it. The mirror creation involves a set of scripts and configuration files required to download a group of RPMs, SRPMs, source code packages and so forth. These tools live inside centos-mirror-tools directory. All items included in this directory must be visble inside the container environment. Then the container shall be run from the same directory where these tools are stored. Basically, we run a container with the previously created StarlingX docker image, using the following configuration: As /localdisk is defined as the workdir of the container, the same folder name should be used to define the volume. The container will start to run and populate logs and output folders in this directory.