[root@2637780b539e /]# ps -ax | grep nginx

15975 ?        Ss     0:00 nginx: master process nginx

31450 ?        S      0:00 nginx: worker process

31451 ?        S      0:00 nginx: worker process

31452 ?        S      0:00 nginx: worker process

31453 ?        S      0:00 nginx: worker process

31454 ?        S      0:00 nginx: worker process

31455 ?        S      0:00 nginx: worker process

31456 ?        S      0:00 nginx: worker process

31457 ?        S      0:00 nginx: worker process

31753 ?        S      0:00 /usr/sbin/nginx

31755 pts/2    S+     0:00 grep --color=auto nginx

[root@2637780b539e /]# cd /

[root@2637780b539e /]# find -name error.log

./var/log/php-fpm/error.log

./var/log/nginx/error.log

[root@2637780b539e /]# cd /var

[root@2637780b539e var]# cd log/nginx/

[root@2637780b539e nginx]# vi error.log 

2015/05/09 08:07:09 [notice] 295#0: signal process started

2015/05/09 08:10:58 [notice] 320#0: signal process started

2015/05/09 08:14:44 [notice] 354#0: signal process started

2015/05/09 08:15:41 [notice] 375#0: signal process started

2015/05/09 08:17:23 [notice] 395#0: signal process started

2015/05/09 08:18:57 [notice] 414#0: signal process started

2015/05/09 08:20:00 [notice] 438#0: signal process started

2015/06/10 08:25:06 [notice] 1418#0: signal process started

2015/06/10 08:25:38 [notice] 1436#0: signal process started

2015/06/11 07:18:01 [notice] 28417#0: signal process started

2015/06/11 07:31:06 [notice] 28657#0: signal process started

2015/06/11 08:29:19 [notice] 29676#0: signal process started

2015/06/11 08:44:06 [notice] 29963#0: signal process started

2015/06/11 08:44:09 [notice] 29973#0: signal process started

2015/06/11 08:49:11 [notice] 30076#0: signal process started

2015/06/11 09:26:54 [notice] 30728#0: signal process started

2015/06/11 09:26:57 [notice] 30738#0: signal process started

2015/06/11 09:35:53 [notice] 30901#0: signal process started

2015/06/16 01:24:37 [notice] 14840#0: signal process started

2015/06/16 01:26:25 [emerg] 14879#0: open() "/etc/nginx/conf/nginx.conf" failed (2: No such file or directory)

2015/06/16 01:59:02 [notice] 15477#0: signal process started

2015/06/16 02:03:02 [emerg] 15556#0: open() "/etc/nginx/nginx.conf" failed (2: No such file or directory)

2015/06/16 02:03:03 [emerg] 15557#0: open() "/etc/nginx/nginx.conf" failed (2: No such file or directory)

2015/06/16 02:03:05 [emerg] 15558#0: open() "/etc/nginx/nginx.conf" failed (2: No such file or directory)

2015/06/16 02:03:08 [emerg] 15559#0: open() "/etc/nginx/nginx.conf" failed (2: No such file or directory)

2015/06/16 02:03:53 [notice] 15560#0: signal process started

2015/06/16 02:03:53 [error] 15560#0: open() "/usr/local/nginx/logs/nginx.pid" failed (2: No such file or directory)

2015/06/16 02:04:44 [notice] 15564#0: signal process started

2015/06/16 02:04:44 [error] 15564#0: open() "/usr/local/nginx/logs/nginx.pid" failed (2: No such file or directory)

2015/06/16 02:06:33 [notice] 15588#0: signal process started

2015/06/16 02:06:33 [error] 15588#0: open() "/usr/local/nginx/logs/nginx.pid" failed (2: No such file or directory)

2015/06/16 02:18:09 [notice] 15594#0: signal process started

2015/06/16 02:18:09 [alert] 15594#0: kill(2526, 1) failed (3: No such process)

2015/06/16 02:18:14 [notice] 15595#0: signal process started

2015/06/16 02:18:14 [alert] 15595#0: kill(2526, 1) failed (3: No such process)