Your default replication factor is probably 3. Since you only have one node, that's impossible to satisfy.

On single-node clusters, you should reduce the replication factor to 1 in HDFS configuration in Cloudera Manager. Note that this only affects newly created files. Your existing files will still try to replicate to 3 hosts unless you change them explicitly (you should be able to google how to change a file's replication factor).

Thanks,
Darren