zabbix问题一：
zabbix_get [2220]: Get value error: cannot connect to [[192.168.247.138]:10050]: [113] No route to host
解决：注意防火墙问题
[root@localhost ~]# systemctl stop firewalld [root@localhost ~]# [root@localhost ~]# [root@localhost ~]# setenforce 0
zabbix问题二：
For passive only agents, host availability is used with 3m as time threshold.
解决：该问题，可能是由于zabbix-agent2.service 服务未启动
[root@localhost ~]# systemctl start zabbix-agent2.service [root@localhost ~]# systemctl status zabbix-agent2.service