問題1： unable to install syscall filter
2017-10-26T16:35:09,186][WARN ][o.e.b.JNANatives ] unable to install syscall filter:
java.lang.UnsupportedOperationException: seccomp unavailable: requires kernel 3.5+ with CONFIG_SECCOMP and CONFIG_SECCOMP_FILTER compiled in
at org.elasticsearch.bootstrap.Seccomp.linuxImpl(Seccomp.java:349) ~[elasticsearch-5.1.1.jar:5.1.1]
at org.elasticsearch.bootstrap.Seccomp.init(Seccomp.java:630) ~[elasticsearch-5.1.1.jar:5.1.1]
at org.elasticsearch.bootstrap.JNANatives.trySeccomp(JNANatives.java:215) [elasticsearch-5.1.1.jar:5.1.1]
at org.elasticsearch.bootstrap.Natives.trySeccomp(Natives.java:99) [elasticsearch-5.1.1.jar:5.1.1]
at org.elasticsearch.bootstrap.Bootstrap.initializeNatives(Bootstrap.java:105) [elasticsearch-5.1.1.jar:5.1.1]
at org.elasticsearch.bootstrap.Bootstrap.setup(Bootstrap.java:176) [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]
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]
解決方法：報了一大串錯誤，其實只是一個警告，可以忽略；也可以升級到最新的linux版本
問題2：vm.max_map_count
[2017-10-26T16:35:12,156][ERROR][o.e.b.Bootstrap ] [node-1] node validation exception
bootstrap checks failed
max virtual memory areas vm.max_map_count [65530] is too low, increase to at least [262144]解決方法：
sudo sysctl -w vm.max_map_count=262144