Hi community,

I'm installing CDH 5.5 on CentOs 6 using the Cloudera Manager.

So far everything works, but formatting the namenode and starting namenode fails with the following error message.

Std. error:

java.io.IOException: Cannot create directory /dfs/nn/current
	at org.apache.hadoop.hdfs.server.common.Storage$StorageDirectory.clearDirectory(Storage.java:337)
	at org.apache.hadoop.hdfs.server.namenode.NNStorage.format(NNStorage.java:548)
	at org.apache.hadoop.hdfs.server.namenode.NNStorage.format(NNStorage.java:569)
	at org.apache.hadoop.hdfs.server.namenode.FSImage.format(FSImage.java:148)
	at org.apache.hadoop.hdfs.server.namenode.NameNode.format(NameNode.java:1041)
	at org.apache.hadoop.hdfs.server.namenode.NameNode.createNameNode(NameNode.java:1479)
	at org.apache.hadoop.hdfs.server.namenode.NameNode.main(NameNode.java:1606)
16/03/04 17:55:11 ERROR namenode.NameNode: Failed to start namenode.

std. our:

Sat Mar  5 17:03:09 CET 2016
JAVA_HOME=/usr/lib/jvm/java-1.7.0-openjdk-1.7.0.95.x86_64/jre
using /usr/lib/jvm/java-1.7.0-openjdk-1.7.0.95.x86_64/jre as JAVA_HOME
using 5 as CDH_VERSION
using /var/run/cloudera-scm-agent/process/43-hdfs-NAMENODE-format as CONF_DIR
using  as SECURE_USER
using  as SECURE_GROUP
64
Formatting using clusterid: cluster16

I'm sure it is a problem with authorization for the user cloudera-scm.

I have added the user in the sudo group (using visudo), but still no success.

Thanks for any advise.

Cheers

Gerd