[root@localhost pazzn]# systemctl status php-fpm.service
● php-fpm-72.service - LSB: starts php-fpm
   Loaded: loaded (/etc/rc.d/init.d/php-fpm-72; bad; vendor preset: disabled)
   Active: inactive (dead)
     Docs: man:systemd-sysv-generator(8)
Warning: php-fpm-72.service changed on disk. Run 'systemctl daemon-reload' to reload units.
[root@localhost pazzn]# systemctl start php-fpm.service
Warning: php-fpm.service changed on disk. Run 'systemctl daemon-reload' to reload units.
Job for php-fpm-72.service failed because the control process exited with error code. See "systemctl status php-fpm-72.service" and "journalctl -xe" for details.
[root@localhost pazzn]# systemctl daemon-reload
[root@localhost pazzn]# systemctl start php-fpm.service
Job for php-fpm-56.service failed because the control process exited with error code. See "systemctl status php-fpm-56.service" and "journalctl -xe" for details.
[root@localhost pazzn]# systemctl start php-fpm-56.service
Job for php-fpm-56.service failed because the control process exited with error code. See "systemctl status php-fpm-56.service" and "journalctl -xe" for details.
[root@localhost pazzn]# systemctl status php-fpm-56.service
● php-fpm-56.service - LSB: starts php-fpm
   Loaded: loaded (/etc/rc.d/init.d/php-fpm-56; bad; vendor preset: disabled)
   Active: failed (Result: exit-code) since Mon 2019-07-22 16:52:47 CST; 7s ago
     Docs: man:systemd-sysv-generator(8)
  Process: 29005 ExecStart=/etc/rc.d/init.d/php-fpm-56 start (code=exited, status=1/FAILURE)

Jul 22 16:52:47 localhost.localdomain systemd[1]: Starting LSB: starts php-fpm...
Jul 22 16:52:47 localhost.localdomain php-fpm-56[29005]: Starting php-fpm [22-Jul-2019 16:52:47] ERROR: An another FPM instance se...6.sock
Jul 22 16:52:47 localhost.localdomain php-fpm-56[29005]: [22-Jul-2019 16:52:47] ERROR: FPM initialization failed
Jul 22 16:52:47 localhost.localdomain php-fpm-56[29005]: failed
Jul 22 16:52:47 localhost.localdomain systemd[1]: php-fpm-56.service: control process exited, code=exited status=1
Jul 22 16:52:47 localhost.localdomain systemd[1]: Failed to start LSB: starts php-fpm.
Jul 22 16:52:47 localhost.localdomain systemd[1]: Unit php-fpm-56.service entered failed state.
Jul 22 16:52:47 localhost.localdomain systemd[1]: php-fpm-56.service failed.
Hint: Some lines were ellipsized, use -l to show in full.
[root@localhost pazzn]# ps -e | grep php-fpm
28745 ?        00:00:00 php-fpm
28746 ?        00:00:00 php-fpm
28747 ?        00:00:00 php-fpm
28748 ?        00:00:00 php-fpm
28749 ?        00:00:00 php-fpm
28750 ?        00:00:00 php-fpm
[root@localhost pazzn]# kill -9 28745
[root@localhost pazzn]# kill -9 28746
[root@localhost pazzn]# kill -9 28747
[root@localhost pazzn]# kill -9 28748
[root@localhost pazzn]# kill -9 28749
[root@localhost pazzn]# kill -9 28750
[root@localhost pazzn]# ps -e | grep php-fpm
[root@localhost pazzn]# systemctl start php-fpm-56.service
[root@localhost pazzn]# systemctl status php-fpm-56.service
● php-fpm-56.service - LSB: starts php-fpm
   Loaded: loaded (/etc/rc.d/init.d/php-fpm-56; bad; vendor preset: disabled)
   Active: active (running) since Mon 2019-07-22 16:53:44 CST; 9s ago
     Docs: man:systemd-sysv-generator(8)
  Process: 29024 ExecStart=/etc/rc.d/init.d/php-fpm-56 start (code=exited, status=0/SUCCESS)
   CGroup: /system.slice/php-fpm-56.service
           ├─29026 php-fpm: master process (/www/server/php/56/etc/php-fpm.conf)
           ├─29027 php-fpm: pool www
           ├─29028 php-fpm: pool www
           ├─29029 php-fpm: pool www
           ├─29030 php-fpm: pool www
           └─29031 php-fpm: pool www

Jul 22 16:53:44 localhost.localdomain systemd[1]: Starting LSB: starts php-fpm...
Jul 22 16:53:44 localhost.localdomain php-fpm-56[29024]: Starting php-fpm  done
Jul 22 16:53:44 localhost.localdomain systemd[1]: Started LSB: starts php-fpm.
[root@localhost pazzn]#