我安装了带有 haproxy 的 CentOS 7.4，我已将其更新到 1.8。 Haproxy无法启动，甚至sudo systemctl start haproxy不显示任何输出。
sudo systemctl status haproxy显示这个：
● haproxy.service - HAProxy Load Balancer
Loaded: loaded (/usr/lib/systemd/system/haproxy.service; enabled; vendor preset: disabled)
Active: inactive (dead) since Wed 2018-01-31 15:17:37 CET; 2s ago
Process: 2807 ExecStart=/usr/sbin/haproxy-systemd-wrapper -f /etc/haproxy/haproxy.cfg -p /run/haproxy.pid $OPTIONS (code=exited, status=0/SUCCESS)
Main PID: 2807 (code=exited, status=0/SUCCESS)
Jan 31 15:17:36 foo systemd[1]: Started HAProxy Load Balancer.
Jan 31 15:17:36 foo systemd[1]: Starting HAProxy Load Balancer...
Jan 31 15:17:37 foo haproxy-systemd-wrapper[2807]: haproxy-systemd-wrapper: executing /usr/sbin/haproxy -f /etc/haproxy/haproxy.cfg -p /run/haproxy.pid -d -Ds
Jan 31 15:17:37 foo haproxy-systemd-wrapper[2807]: haproxy-systemd-wrapper: exit, haproxy RC=0
日志不会产生太多有用的信息：
Jan 31 15:19:43 foo systemd[1]: Started HAProxy Load Balancer.
-- Subject: Unit haproxy.service has finished start-up
-- Defined-By: systemd
-- Support: http://lists.freedesktop.org/mailman/listinfo/systemd-devel
--
-- Unit haproxy.service has finished starting up.
--
-- The start-up result is done.
Jan 31 15:19:43 awisot3 systemd[1]: Starting HAProxy Load Balancer...
-- Subject: Unit haproxy.service has begun start-up
-- Defined-By: systemd
-- Support: http://lists.freedesktop.org/mailman/listinfo/systemd-devel
--
-- Unit haproxy.service has begun starting up.
当我尝试模拟 systemd 的功能并执行 a 时，sudo -u haproxy usr/sbin/haproxy -f /etc/haproxy/haproxy.cfg -p /run/haproxy.pid -d -Ds我收到以下错误消息：
[WARNING] 030/152521 (3031) : [/usr/sbin/haproxy.main()] Cannot raise FD limit to 8015, limit is 4096.
[ALERT] 030/152521 (3031) : [/usr/sbin/haproxy.main()] Cannot create pidfile /run/haproxy.pid
如何正确设置对haproxy.pid和 的访问/run？额外问题：为什么journalctl也不披露这些信息？