Hello: I have followed this link:http://code.google.com/p/hadoop-gpl- compression/wiki/FAQ to install lzo compression library,and copy hadoop-lzo-0.4.4.jar to $HADOOP_HOME/lib,and all files under ..lib/native/Linux-amd64-64 to $HADOOP_HOME/lib/native/Linux-amd64-64, and run example,but got this errors: ---------------------------------------------------------------------------------------------------------------- Exception in thread "main" java.lang.IllegalArgumentException: Compression codec org.apache.hadoop.io.compress.GzipCodec not found. at org.apache.hadoop.io.compress.CompressionCodecFactory.getCodecClasses(CompressionCodecFactory.java:96) at org.apache.hadoop.io.compress.CompressionCodecFactory.<init>(CompressionCodecFactory.java:134) at com.hadoop.compression.lzo.LzoIndex.createIndex(LzoIndex.java:202) at com.hadoop.compression.lzo.LzoIndexer.indexSingleFile(LzoIndexer.java:117) at com.hadoop.compression.lzo.LzoIndexer.indexInternal(LzoIndexer.java:98) at com.hadoop.compression.lzo.LzoIndexer.index(LzoIndexer.java:52) at com.hadoop.compression.lzo.LzoIndexer.main(LzoIndexer.java:137) at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39) at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25) at java.lang.reflect.Method.invoke(Method.java:597) at org.apache.hadoop.util.RunJar.main(RunJar.java:156) Caused by: java.lang.ClassNotFoundException: org.apache.hadoop.io.compress.GzipCodec at java.net.URLClassLoader$1.run(URLClassLoader.java:202) at java.security.AccessController.doPrivileged(Native Method) at java.net.URLClassLoader.findClass(URLClassLoader.java:190) at java.lang.ClassLoader.loadClass(ClassLoader.java:307) at java.lang.ClassLoader.loadClass(ClassLoader.java:248) at java.lang.Class.forName0(Native Method) at java.lang.Class.forName(Class.java:247) at org.apache.hadoop.conf.Configuration.getClassByName(Configuration.java:762) at org.apache.hadoop.io.compress.CompressionCodecFactory.getCodecClasses(CompressionCodecFactory.java:89) ... 11 more
---------------------------------------------------------------------------------------------------------------- and then I try to add this to hadoop-env.sh: export HADOOP_CLASSPATH=$HADOOP_CLASSPATH:/usr/local/hadoop/hadoop-0.20.2/lib/ Same problem as before,this problem is killing me,because it has surrounded me for one month.