For debugging purposes, you might want to inspect the system after installation has been completed but before it is rebooted. You can override requests for automatic booting contained in a manifest file or in boot command arguments by creating the file /system/volatile/noautoreboot.
To prevent an automatic reboot after the installation, log in to the target client system and type the following command:
$ touch /system/volatile/noautoreboot
Then begin the automatic installation. At the end of the installation, the process checks for the presence of the file. If the file is detected, installation ends and you can begin diagnosing the system.