常见错误

1.jps没有datanode进程

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2015-04-16 16:14:49,728 INFO org.apache.hadoop.hdfs.server.datanode.DataNode: registered UNIX signal handlers for [TERM, HUP, INT]
2015-04-16 16:14:51,568 WARN org.apache.hadoop.hdfs.server.datanode.DataNode: Invalid dfs.datanode.data.dir /usr/local/hadoop-2.6.0/hdfs/data :
EPERM: Operation not permitted
    at org.apache.hadoop.io.nativeio.NativeIO$POSIX.chmodImpl(Native Method)
    at org.apache.hadoop.io.nativeio.NativeIO$POSIX.chmod(NativeIO.java:230)
    at org.apache.hadoop.fs.RawLocalFileSystem.setPermission(RawLocalFileSystem.java:652)
    at org.apache.hadoop.fs.FilterFileSystem.setPermission(FilterFileSystem.java:490)
    at org.apache.hadoop.util.DiskChecker.mkdirsWithExistsAndPermissionCheck(DiskChecker.java:140)
    at org.apache.hadoop.util.DiskChecker.checkDir(DiskChecker.java:156)

master@master-VirtualBox:/usr/local/hadoop-2.6.0/dfs$ sudo chown -R master:adm data
master@master-VirtualBox:/usr/local/hadoop-2.6.0/dfs$ sudo chmod -R 777 data