How can I change the hostname of Raspberry Digital Signage?
Default hostname for the operating system is rds. You can change it by modifying the /etc/hostname and /etc/hosts files.
Also, in the /rds/home/rds-user/chromium-default-settings.tar there are three files called Singleton*. One of them, SingletonLock -> rds-xxxx, is the issue. Once this file is removed, sysrtem works with the new hostname (as Chromium creates SingletonLock file with the correct new hostname).