I ran namenode -format.This is my output. I tried changing the file permissions chmod 777 hadoop.
I believe this line is the error ERROR namenode.NameNode: java.io.IOException: Cannot create directory /your/path/to/hadoop/tmp/dir/hadoop-hadoop/dfs/name/current
adoop@alexander-desktop:/usr/local/hadoop/bin$ ./hadoop namenode -format
12/07/03 17:03:56 INFO namenode.NameNode: STARTUP_MSG:
/************************************************************
STARTUP_MSG: Starting NameNode
STARTUP_MSG: host = alexander-desktop/127.0.1.1
STARTUP_MSG: args = [-format]
STARTUP_MSG: version = 0.20.2
STARTUP_MSG: build = https://svn.apache.org/repos/asf/hadoop/common/branches/branch-0.20 -r 911707; compiled by 'chrisdo' on Fri Feb 19 08:07:34 UTC 2010
************************************************************/
12/07/03 17:03:56 INFO namenode.FSNamesystem: fsOwner=hadoop,hadoop
12/07/03 17:03:56 INFO namenode.FSNamesystem: supergroup=supergroup
12/07/03 17:03:56 INFO namenode.FSNamesystem: isPermissionEnabled=true
12/07/03 17:03:56 ERROR namenode.NameNode: java.io.IOException: Cannot create directory /your/path/to/hadoop/tmp/dir/hadoop-hadoop/dfs/name/current
at org.apache.hadoop.hdfs.server.common.Storage$StorageDirectory.clearDirectory(Storage.java:295)
at org.apache.hadoop.hdfs.server.namenode.FSImage.format(FSImage.java:1086)
at org.apache.hadoop.hdfs.server.namenode.FSImage.format(FSImage.java:1110)
at org.apache.hadoop.hdfs.server.namenode.NameNode.format(NameNode.java:856)
at org.apache.hadoop.hdfs.server.namenode.NameNode.createNameNode(NameNode.java:948)
at org.apache.hadoop.hdfs.server.namenode.NameNode.main(NameNode.java:965)
12/07/03 17:03:56 INFO namenode.NameNode: SHUTDOWN_MSG:
/************************************************************
SHUTDOWN_MSG: Shutting down NameNode at alexander-desktop/127.0.1.1
hadoop@alexander-desktop:/usr/local$ sudo hadoop/bin/hadoop namenode -format
sudo: /etc/sudoers is mode 0777, should be 0440
sudo: no valid sudoers sources found, quitting
try with sudo (I realize you changed permissions) but I would still try sudo and check if that resolves the problem.