http://cccpastefzuz6unowzgjtdwmxwjfgf5za7owwci3b2zys4jmc3xjszad.onion/cccea7c18ebdb7dd
So if this file does not exist, the extroot will not be configured. This allows one to easily disable setting up the crypto disk early on, thus effectively disabling extroot. Once on the extroot, to access this file you'll need to mount the rootfs_data, or you could turn off the device, remove the extroot block device, and boot without it.