检查初始状态

Linux系统一些常见命令：https://www.cnblogs.com/wangkongming/p/4531341.html

1 首先查看linux当前的操作系统发布信息：

[root@izgslmnd8h32fxz ~]# cat /etc/redhat-release

CentOS Linux release 7.4.1708 (Core)

2 查看阿里云提供的镜像服务器上有哪些服务：

[root@izgslmnd8h32fxz ~]# chkconfig --list

Note: This output shows SysV services only and does not include native
      systemd services. SysV configuration data might be overridden by native
      systemd configuration.

      If you want to list systemd services use 'systemctl list-unit-files'.
      To see services enabled on particular target use
      'systemctl list-dependencies [target]'.

aegis           0:off   1:off   2:on    3:on    4:on    5:on    6:off
agentwatch      0:off   1:off   2:on    3:on    4:on    5:on    6:off
netconsole      0:off   1:off   2:off   3:off   4:off   5:off   6:off
network         0:off   1:off   2:on    3:on    4:on    5:on    6:off

3 由此可以判断阿里云服务器上基本什么都没有安装，也意味着我们需要亲自搭建各种环境（jdk，tomcat，mysql，maven私服，nginx，zookeper，dubbo，redis，jms，fastdfs等）