I look in the name node log and I get the following errors:
2013-04-29 15:25:11,646 ERROR org.apache.hadoop.security.UserGroupInformation: PriviledgedActionException as:mapred (auth:SIMPLE) cause:org.apache.hadoop.security.AccessControlException: Permission denied: user=mapred, access=WRITE, inode="/":hdfs:supergroup:drwxr-xr-x
2013-04-29 15:25:11,646 INFO org.apache.hadoop.ipc.Server: IPC Server handler 6 on 9000, call org.apache.hadoop.hdfs.protocol.ClientProtocol.mkdirs from 172.16.26.68:45044: error: org.apache.hadoop.security.AccessControlException: Permission denied: user=mapred, access=WRITE, inode="/":hdfs:supergroup:drwxr-xr-x org.apache.hadoop.security.AccessControlException: Permission denied: user=mapred, access=WRITE, inode="/":hdfs:supergroup:drwxr-xr-x at org.apache.hadoop.hdfs.server.namenode.FSPermissionChecker.check(FSPermissionChecker.java:205) at org.apache.hadoop.hdfs.server.namenode.FSPermissionChecker.check(FSPermissionChecker.java:186)
When I create the file system I have the user hdfs on the root folder. (/). I am not sure now to have both the user mapred and hdfs have access to the root (which it seems these errors are indicating).
I get a page from 50070 put when I try to browse the filesystem from the web UI I get an error that there are no nodes listening (I have 3 data nodes and 1 namenode). The browser indicates that there is nothing listening to port 50030, so it seems that the JobTracker is not up.
