出现错误：

root@ubuntu:~/software/elasticsearch$ ./bin/elasticsearch
[2017-03-23T18:14:05,880][INFO ][o.e.n.Node               ] [] initializing ...
[2017-03-23T18:14:06,151][INFO ][o.e.e.NodeEnvironment    ] [r5Eus3r] using [1] data paths, mounts [[/ (/dev/sda1)]], net usable_space [11.1gb], net total_space [17.5gb], spins? [possibly], types [ext4]
[2017-03-23T18:14:06,152][INFO ][o.e.e.NodeEnvironment    ] [r5Eus3r] heap size [1.9gb], compressed ordinary object pointers [true]
[2017-03-23T18:14:06,154][INFO ][o.e.n.Node               ] [r5Eus3r] node name [r5Eus3r] derived from node ID; set [node.name] to override
[2017-03-23T18:14:06,171][INFO ][o.e.n.Node               ] [r5Eus3r] version[5.0.1], pid[3669], build[080bb47/2016-11-11T22:08:49.812Z], OS[Linux/4.8.0-41-generic/amd64], JVM[Oracle Corporation/Java HotSpot(TM) 64-Bit Server VM/1.8.0_121/25.121-b13]
[2017-03-23T18:14:08,104][INFO ][o.e.p.PluginsService     ] [r5Eus3r] loaded module [aggs-matrix-stats]
[2017-03-23T18:14:08,110][INFO ][o.e.p.PluginsService     ] [r5Eus3r] loaded module [ingest-common]
[2017-03-23T18:14:08,110][INFO ][o.e.p.PluginsService     ] [r5Eus3r] loaded module [lang-expression]
[2017-03-23T18:14:08,111][INFO ][o.e.p.PluginsService     ] [r5Eus3r] loaded module [lang-groovy]
[2017-03-23T18:14:08,111][INFO ][o.e.p.PluginsService     ] [r5Eus3r] loaded module [lang-mustache]
[2017-03-23T18:14:08,111][INFO ][o.e.p.PluginsService     ] [r5Eus3r] loaded module [lang-painless]
[2017-03-23T18:14:08,111][INFO ][o.e.p.PluginsService     ] [r5Eus3r] loaded module [percolator]
[2017-03-23T18:14:08,111][INFO ][o.e.p.PluginsService     ] [r5Eus3r] loaded module [reindex]
[2017-03-23T18:14:08,112][INFO ][o.e.p.PluginsService     ] [r5Eus3r] loaded module [transport-netty3]
[2017-03-23T18:14:08,112][INFO ][o.e.p.PluginsService     ] [r5Eus3r] loaded module [transport-netty4]
[2017-03-23T18:14:08,113][INFO ][o.e.p.PluginsService     ] [r5Eus3r] no plugins loaded
[2017-03-23T18:14:12,904][INFO ][o.e.n.Node               ] [r5Eus3r] initialized
[2017-03-23T18:14:12,905][INFO ][o.e.n.Node               ] [r5Eus3r] starting ...
[2017-03-23T18:14:13,161][INFO ][o.e.t.TransportService   ] [r5Eus3r] publish_address {127.0.0.1:9300}, bound_addresses {[::]:9300}
[2017-03-23T18:14:13,165][INFO ][o.e.b.BootstrapCheck     ] [r5Eus3r] bound or publishing to a non-loopback or non-link-local address, enforcing bootstrap checks

解决办法：
1、切换到root用户修改配置sysctl.conf

添加下面配置：

并执行命令：

然后，重新启动elasticsearch，即可启动成功。