$ ./elasticsearch
[2017-01-15T22:31:49,803][INFO ][o.e.n.Node               ] [] initializing ...
[2017-01-15T22:31:50,846][INFO ][o.e.e.NodeEnvironment    ] [HKKO5nk] using [1] data paths, mounts [[/ (/dev/sda1)]], net usable_space [30.7gb], net total_space [38.2gb], spins? [possibly], types [ext4]
[2017-01-15T22:31:50,849][INFO ][o.e.e.NodeEnvironment    ] [HKKO5nk] heap size [1.9gb], compressed ordinary object pointers [true]
[2017-01-15T22:31:50,863][INFO ][o.e.n.Node               ] node name [HKKO5nk] derived from node ID [HKKO5nkzSHWMEhojiWQK3g]; set [node.name] to override
[2017-01-15T22:31:50,950][INFO ][o.e.n.Node               ] version[5.1.1], pid[3167], build[5395e21/2016-12-06T12:36:15.409Z], OS[Linux/3.13.0-24-generic/amd64], JVM[Oracle Corporation/Java HotSpot(TM) 64-Bit Server VM/1.8.0_111/25.111-b14]
[2017-01-15T22:32:04,168][INFO ][o.e.p.PluginsService     ] [HKKO5nk] loaded module [aggs-matrix-stats]
[2017-01-15T22:32:04,168][INFO ][o.e.p.PluginsService     ] [HKKO5nk] loaded module [ingest-common]
[2017-01-15T22:32:04,169][INFO ][o.e.p.PluginsService     ] [HKKO5nk] loaded module [lang-expression]
[2017-01-15T22:32:04,169][INFO ][o.e.p.PluginsService     ] [HKKO5nk] loaded module [lang-groovy]
[2017-01-15T22:32:04,169][INFO ][o.e.p.PluginsService     ] [HKKO5nk] loaded module [lang-mustache]
[2017-01-15T22:32:04,169][INFO ][o.e.p.PluginsService     ] [HKKO5nk] loaded module [lang-painless]
[2017-01-15T22:32:04,169][INFO ][o.e.p.PluginsService     ] [HKKO5nk] loaded module [percolator]
[2017-01-15T22:32:04,170][INFO ][o.e.p.PluginsService     ] [HKKO5nk] loaded module [reindex]
[2017-01-15T22:32:04,170][INFO ][o.e.p.PluginsService     ] [HKKO5nk] loaded module [transport-netty3]
[2017-01-15T22:32:04,171][INFO ][o.e.p.PluginsService     ] [HKKO5nk] loaded module [transport-netty4]
[2017-01-15T22:32:04,172][INFO ][o.e.p.PluginsService     ] [HKKO5nk] no plugins loaded
[2017-01-15T22:32:10,411][WARN ][o.e.b.ElasticsearchUncaughtExceptionHandler] [] uncaught exception in thread [main]
org.elasticsearch.bootstrap.StartupException: java.lang.IllegalArgumentException: unknown setting [http.cors.enable] did you mean [http.cors.enabled]?
    at org.elasticsearch.bootstrap.Elasticsearch.init(Elasticsearch.java:125) ~[elasticsearch-5.1.1.jar:5.1.1]
    at org.elasticsearch.bootstrap.Elasticsearch.execute(Elasticsearch.java:112) ~[elasticsearch-5.1.1.jar:5.1.1]
    at org.elasticsearch.cli.SettingCommand.execute(SettingCommand.java:54) ~[elasticsearch-5.1.1.jar:5.1.1]
    at org.elasticsearch.cli.Command.mainWithoutErrorHandling(Command.java:96) ~[elasticsearch-5.1.1.jar:5.1.1]
    at org.elasticsearch.cli.Command.main(Command.java:62) ~[elasticsearch-5.1.1.jar:5.1.1]
    at org.elasticsearch.bootstrap.Elasticsearch.main(Elasticsearch.java:89) ~[elasticsearch-5.1.1.jar:5.1.1]
    at org.elasticsearch.bootstrap.Elasticsearch.main(Elasticsearch.java:82) ~[elasticsearch-5.1.1.jar:5.1.1]
Caused by: java.lang.IllegalArgumentException: unknown setting [http.cors.enable] did you mean [http.cors.enabled]?
    at org.elasticsearch.common.settings.AbstractScopedSettings.validate(AbstractScopedSettings.java:278) ~[elasticsearch-5.1.1.jar:5.1.1]
    at org.elasticsearch.common.settings.AbstractScopedSettings.validate(AbstractScopedSettings.java:246) ~[elasticsearch-5.1.1.jar:5.1.1]
    at org.elasticsearch.common.settings.SettingsModule.<init>(SettingsModule.java:138) ~[elasticsearch-5.1.1.jar:5.1.1]
    at org.elasticsearch.node.Node.<init>(Node.java:325) ~[elasticsearch-5.1.1.jar:5.1.1]
    at org.elasticsearch.node.Node.<init>(Node.java:229) ~[elasticsearch-5.1.1.jar:5.1.1]
    at org.elasticsearch.bootstrap.Bootstrap$6.<init>(Bootstrap.java:214) ~[elasticsearch-5.1.1.jar:5.1.1]
    at org.elasticsearch.bootstrap.Bootstrap.setup(Bootstrap.java:214) ~[elasticsearch-5.1.1.jar:5.1.1]
    at org.elasticsearch.bootstrap.Bootstrap.init(Bootstrap.java:306) ~[elasticsearch-5.1.1.jar:5.1.1]
    at org.elasticsearch.bootstrap.Elasticsearch.init(Elasticsearch.java:121) ~[elasticsearch-5.1.1.jar:5.1.1]
    ... 6 more

log说的很明白了
org.elasticsearch.bootstrap.StartupException: java.lang.IllegalArgumentException: unknown setting [http.cors.enable] did you mean [http.cors.enabled]
 
5.0以后在启动时加入了参数检查，参数如果不合法会报错