方式1（不推荐）：注释hadoop-config.sh中的
if [ "$HADOOP_HOME_WARN_SUPPRESS" = "" ] && [ "$HADOOP_HOME" != "" ]; then
echo "Warning: \$HADOOP_HOME is deprecated." 1>&2
echo 1>&2
fi
方式2:：修改环境变量
可以是用当前用户的环境变量也可以是全局环境变量
添加 export HADOOP_HOME_WARN_SUPPRESS=1
source /etc/profile 立即生效
测试警告消失！
[root@h1 conf]# hadoop fs -help
hadoop fs is the command to execute fs commands. The full syntax is:
hadoop fs [-fs <local | file system URI>] [-conf <configuration file>]
[-D <property=value>] [-ls <path>] [-lsr <path>] [-du <path>]
[-dus <path>] [-mv <src> <dst>] [-cp <src> <dst>] [-rm [-skipTrash] <src>]
[-rmr [-skipTrash] <src>] [-put <localsrc> ... <dst>] [-copyFromLocal <localsrc> ... <dst>]
[-moveFromLocal <localsrc> ... <dst>] [-get [-ignoreCrc] [-crc] <src> <localdst>
[-getmerge <src> <localdst> [addnl]] [-cat <src>]
[-copyToLocal [-ignoreCrc] [-crc] <src> <localdst>] [-moveToLocal <src> <localdst>]