# redis-cli
>config get requirepass
>config set requirepass <password>
>config rewrite
>shutdown
>quit
# ./redis-server redis.conf
# redis-cli
>auth <password>
>info
# redis-cli
>config get requirepass
>config set requirepass <password>
>config rewrite
>shutdown
>quit
# ./redis-server redis.conf
# redis-cli
>auth <password>
>info