笔者实验环境：centos 7.4.1708，hadoop-2.6.0-cdh5.14.2.
执行hadoop命令时出现以下告警，不能加载相关库：
WARN util.NativeCodeLoader: Unable to load native-hadoop library for your platform... using builtin-java classes where applicable
检查发现本地并没有库：
$ hadoop checknative -a
19/08/30 13:11:53 WARN util.NativeCodeLoader: Unable to load native-hadoop library for your platform... using builtin-java classes where applicable
Native library checking:
hadoop: false
zlib: false
snappy: false
lz4: false
bzip2: false
openssl: false
19/08/30 13:11:53 INFO util.ExitUtil: Exiting with status 1
进入到hadoop目录下可以看到/lib/native为空。
需要下载对应版本的库文件：http://dl.bintray.com/sequenceiq/sequenceiq-bin/
此处笔者选择：hadoop-native-64-2.6.0.tar。
下载解压至hadoop目录下的/lib/native中：
$ ll
total 4356
-rw-r--r-- 1 hadoop hadoop 1119486 Dec 2 2014 libhadoop.a
-rw-r--r-- 1 hadoop hadoop 1486964 Dec 2 2014 libhadooppipes.a
lrwxrwxrwx 1 hadoop hadoop 18 Dec 2 2014 libhadoop.so -> libhadoop.so.1.0.0
-rwxr-xr-x 1 hadoop hadoop 671189 Dec 2 2014 libhadoop.so.1.0.0
-rw-r--r-- 1 hadoop hadoop 581944 Dec 2 2014 libhadooputils.a
-rw-r--r-- 1 hadoop hadoop 359458 Dec 2 2014 libhdfs.a
lrwxrwxrwx 1 hadoop hadoop 16 Dec 2 2014 libhdfs.so -> libhdfs.so.0.0.0
-rwxr-xr-x 1 hadoop hadoop 228435 Dec 2 2014 libhdfs.so.0.0.0
重启dfs，问题解决：(笔者已经配置好hadoop环境变量，直接运行命令)
$ start-dfs.sh
$ hdfs dfs -ls /
Found 2 items
drwxr-xr-x - hadoop supergroup 0 2019-08-29 15:08 /test
drwx------ - hadoop supergroup 0 2019-08-29 15:08 /tmp