一、现象

因为 es 不允许使用root用户安装，在使用新建的es用户安装的时候报错如下，

max file descriptors [4096] for elasticsearch process is too low, increase to at least [65535]

ERROR: [3] bootstrap checks failed. You must address the points described in the following [3] lines before starting Elasticsearch.
bootstrap check failure [1] of [3]: max file descriptors [4096] for elasticsearch process is too low, increase to at least [65535]
bootstrap check failure [2] of [3]: max virtual memory areas vm.max_map_count [65530] is too low, increase to at least [262144]
bootstrap check failure [3] of [3]: the default discovery settings are unsuitable for production use; at least one of [discovery.seed_hosts, discovery.seed_providers, clust

二、解决办法

将当前用户的软硬限制调大。找到文件 /etc/security/limits.conf，编辑，在文件的最后追加如下配置：

es soft nofile 65535
es hard nofile 65537

说明： soft nofile表示软限制，hard nofile表示硬限制。两行语句表示，es用户的软限制为65535，硬限制为65537，即表示es用户能打开的最大文件数量为65537，不管它开启多少个shell。