重启nginx是出现了如下错误：

nginx: [emerg] unknown log format “main” in /usr/local/nginx/nginx.conf:124

解决办法：

打开nginx.conf，”main”错误是因为丢失了log_format选项，默认把他屏蔽掉了，修改之后问题解决

http {
    include       mime.types;
    default_type  application/octet-stream;
#取消以下三行注释
    log_format  main  '$remote_addr - $remote_user [$time_local] "$request" '
                      '$status $body_bytes_sent "$http_referer" '
                      '"$http_user_agent" "$http_x_forwarded_for"';

    #access_log  logs/access.log  main;