From Audirvana’s instructions on how to install in Linux:
To start automatically Audirvāna Studio/Audirvāna Origin as a service at boot, a shell script setAsService.sh can be found in the same folder.
So you would go to the folder where Audirvana is installed, open a terminal there and issue the command:
sudo ./setAsService.sh
Information should then appear in the terminal about how to proceed if I remember correctly.