区分不同的网站有三种方式:
1、ip区分
2、端口区分
3、域名区分

基于ip的虚拟主机配置
    server {
        listen       80;
        server_name  192.168.11.181;
        
        location / {
            root   html-181;
            index  index.html index.htm;
        }
        
        error_page   500 502 503 504  /50x.html;
        location = /50x.html {
            root   html;
        }
    }
    server {
        listen       80;
        server_name  192.168.11.182;
        
        location / {
            root   html-182;
            index  index.html index.htm;
        }
        
        error_page   500 502 503 504  /50x.html;
        location = /50x.html {
            root   html;
        }
    }

基于端口的虚拟主机
    server {
        listen       80;
        server_name  192.168.11.182;
        
        location / {
            root   html-182;
            index  index.html index.htm;
        }
        
        error_page   500 502 503 504  /50x.html;
        location = /50x.html {
            root   html;
        }
    }
    server {
        listen       81;
        server_name  192.168.11.182;
        
        location / {
            root   html-81;
            index  index.html index.htm;
        }
        
        error_page   500 502 503 504  /50x.html;
        location = /50x.html {
            root   html;
        }
    }    
基于域名的虚拟主机
    server {
        listen       80;
        server_name  www.fuyi.com;
        
        location / {
            root   html-181;
            index  index.html index.htm;
        }
        
        error_page   500 502 503 504  /50x.html;
        location = /50x.html {
            root   html;
        }
    } 
    server {
        listen       80;
        server_name  m.fuyi.com;
        
        location / {
            root   html-182;
            index  index.html index.htm;
        }
        
        error_page   500 502 503 504  /50x.html;
        location = /50x.html {
            root   html;
        }
    }