ES启动失败，报错如下
分析原因：
/tmp is mounted non-exec，需要给exec
https://stackoverflow.com/questions/13502156/what-are-possible-causes-of-failed-to-map-segment-from-shared-object-operation
参考：https://stackoverflow.com/questions/35418018/spark-returns-error-libsnappyjava-so-failed-to-map-segment-from-shared-object
官方从6.4版本开始给的解释：https://www.elastic.co/guide/en/elasticsearch/reference/6.8/executable-jna-tmpdir.html
解决办法：
方法一：sudo mount /tmp -o remount,exec
参考：https://blog.csdn.net/baidu_30809315/article/details/103959376
方法二： 配置JVM flag -Djna.tmpdir=<path>
