1、提示文件描述符数量太少，修改/etc/security/limits.conf文件，添加。
* hard nofile 65536
* soft nofile 65536
2、max virtual memory areas vm.max_map_count [65530] likely too low, increase to at least [262144]
/etc/sysctl.conf 文件添加 vm.max_map_count=262144
sysctl -p
3、system call filters failed to install; check the logs and fix your configuration or disable system call filters at your own risk
原因：
这是在因为Centos6不支持SecComp，而ES5.2.0默认bootstrap.system_call_filter为true进行检测，所以导致检测失败，失败后直接导致ES不能启动。
解决：
在elasticsearch.yml中配置bootstrap.system_call_filter为false，注意要在Memory下面:
bootstrap.memory_lock: false
bootstrap.system_call_filter: false
4、实例配置
path.data: /opt/data/elasticsearch
path.logs: /opt/logs/elasticsearch
bootstrap.memory_lock: false
bootstrap.system_call_filter: false
network.host: 0.0.0.0
http.port: 9200
