Hi Jiri,
I'm having the same hdfs issue using the hortonworks sandbox 2.5. I can connect and browse files and hive tables, however when I try to upload a file or a table from my local windows I get the error "File test.txt could only be replicated to - nodes instead of minReplication =1, There are 1 datanodes running and i nodes are excluded in this operations." Everything works fine with Ambari: I can load files and tables.
I set the user define variable dfs.client.use.datanode.hostname as described above, all other configurations are pretty much out-of the box. I'm not using Kerberos security.
What else can I check?
Thanks