Description of problem:

No pid file created tu pidfile present into systemd unit.
Redis not started as a daemon but package as it.

Version-Release number of selected component (if applicable):

[root@mgbshipf01 run]# rpm -qa | grep redis
redis-2.4.15-3.fc18.x86_64

How reproducible:

yum install redis
systemctl start redis.service

Steps to Reproduce:
1. Install redis
2. start it
3.

Actual results:

Redis is running but no pid created

Expected results:

Redis running in a daemonized form and create a pid

Additional info:

Remember that redis is forking 1 time and does not check if redis daemon is already running !

void daemonize(void) {
    int fd;

    if (fork() != 0) exit(0); /* parent exits */
    setsid(); /* create a new session */

    /* Every output goes to /dev/null. If Redis is daemonized but
     * the 'logfile' is set to 'stdout' in the configuration file
     * it will not log at all. */
    if ((fd = open("/dev/null", O_RDWR, 0)) != -1) {
        dup2(fd, STDIN_FILENO);
        dup2(fd, STDOUT_FILENO);
        dup2(fd, STDERR_FILENO);
        if (fd > STDERR_FILENO) close(fd);
    }
}