如何安装hadoop

wget -
4-0.x86_64.rpm
yum --nogpgcheck localinstall cloudera-cdh-4-0.x86_64.rpm
rpm --import
yum install hadoop-0.20-conf-pseudo
sudo -u hdfs hdfs namenode –format
service hadoop-hdfs-namenode start
service hadoop-hdfs-datanode start
service hadoop-0.20-mapreduce-jobtracker start
Service hadoop-0.20-mapreduce-tasktracker star

Cloudera官方安装文档：
cloudera-docs/CDH4/latest/CDH4-Quick-Start/cdh4qs_topic_3_2.html