I am posting this answer after searching in the internet for a good explanation. Currently the total physical hard disk space (4 nodes) is 720 GB. The dashboard currently shows that only 119 GB is configured for DFS. I want to increase this space to at last 300 GB. I didn't find anything staright forward on Ambari dashboard to do this. The only information I found on the internet is to modifify core-site.xml file to hav a property hadoop.tmp.dir pr that points to another directory. I do not want to blankly do it, without understanding what it means to be expanding HDFS capacity and how to do it through Ambari Dashboard. ... View more

I have a four node Ambari cluster. When I look at the DFS usage on the Ambari main dashboard and look at the disk space on individual hosts, I get different figures. Following are the figures that I see on the main dashboard HDFS Disk Usage DFS used 49.7 GB (25.84%) Non-DFS 66 GB (34.64%) Remaining 76.1 GB (39.52%) If I see the the disk space for the individual hosts, then I see the following. host1: 28.07 GB/138.87 GB (20.21% used) host2: 27.45 GB/138.87 GB (19.77% used) host3: 31.45 GB/221.63 GB (14.19% used) host4: 77.38 GB/221.38 GB (34% used) So if you see the disk space in GB for each host is more than the total disk space shown under the HDFS disk usage. I am not able to relate these two figures. Also, I would like to understand whether there is a any documentation that explains the different sections of the Ambari Dashboard. ... View more

I have created a "Files" view successfully. But, when I click on the file view, I see the following error on the top 500 User: root is not allowed to impersonate admin I know this has to do something with impersonation. I read this post in hortonworks community to understand the cause and fix for this issue https://community.hortonworks.com/questions/153/impersonation-error-while-trying-to-access-ambari.html As suggested in the above thread, I am trying to set the hadoop.proxyuser.root.groups and hadoop.proxyuser.root.host, through the advance config under "HDFS -> Configs -> Advanced" tab. But I am not able to find the above two properties under "Advanced core-site" section. I only see ProxyUserGroups property under "Advanced hadoop-env" section, but I am not sure whether this is the property I need to change. Anybody has any idea about this issue and how to fix it? ... View more