Comment 4 for bug 1073110

lava-command can let you specify commands which you want to run in the target in job file directly, you may use the following job to partition disks and format it.
{
            "command": "lava_command_run",
            "parameters": {
                "commands": [
                    "echo '1,16,L' | sfdisk -uM /dev/sda",
                    "mkfs.ext4 /dev/sda1"
                ]
            }
}