Failed to start redis.service: Unit redis-server.service is masked
问题 I Installed Redis Server on ubuntu 16.04. but when I try to start the redis service as $ sudo systemctl start redis I receive message: Failed to start redis.service: Unit redis-server.service is masked. I don't have any idea about this error. 回答1: I found the solution. I think it will help for others | systemctl unmask servicename $ sudo systemctl unmask redis-server.service 回答2: if redis.service file is missed in directory path /etc/systemd/system/redis.service so we have to create file into