Hadoop NFS gateway - mount failed: No such file or directory

I'm trying to mount my HDFS using the NFS gateway as it is documented here: http://hadoop.apache.org/docs/r2.7.1/hadoop-project-dist/hadoop-hdfs/HdfsNfsGateway.html

Unfortunately, following the documentation step by step does not work for me (Hadoop 2.7.1 on CentOS 6.6). When executing the mount command I receive the following error message:

[root@server1 ~]# mount -t nfs -o vers=3,proto=tcp,nolock,noacl,sync server1:/ /hdfsmount/ mount.nfs: mounting server1:/ failed, reason given by server: No such file or directory

I created the folder hdfsmount so that I can say it definitely exists. My questions are now:

Did anyone faced the same issue as I do?
Do I have to configure the NFS server before I start following the steps in the documentation (e.g. I read about editing /etc/exports).

Any help is highly apreciated!

Solution

I found the problem deep in the logs. When executing the command (see below) to start the nfs3 component of HDFS, the executing user needs permissions to delete /tmp/.hdfs-nfs which is configured as nfs.dump.dir in core-site.xml.

If the permissions are not set, you'll receive a log message like:

15/08/12 01:19:56 WARN fs.FileUtil: Failed to delete file or dir [/tmp/.hdfs-nfs]: it still exists. Exception in thread "main" java.io.IOException: Cannot remove current dump directory: /tmp/.hdfs-nfs

Another option is to simply start the nfs component as root.

[root]> /usr/local/hadoop/sbin/hadoop-daemon.sh --script /usr/local/hadoop/bin/hdfs start nfs3