following steps worked for me in my case the node (#4) had disk failures was not coming up as data node ; was stopped i tried starting it thougth services>hdfs>node4>start this data node but failed while looking at logs o found warnings about more than one drives having data inconcistency; theere were FATAL messages but those lead me to dead end while searching for solution. i went to all those mounted points(disks) and removed dfs by rm -rf /dfs on node; one of drive was unable to mount  beacuse on that local location hdfs already made those folders; due to pervious attempts of starting datanode; i removed those folders as well and was able to mount. once mounted the new disk was clean free of any hadoop folders I found a file in /tmp/hsprfdata_hdfs which began with some numbers (was some kind of log); i renamed it as old_**** just in case I need it later; and let hdfs know that file is gone!!! i went back to CDH manager HDFS node 4 and tried restarting this datanode; it worked; all the disks have dfs and directories now; tmp location had that old_*** file removed and there is new file (some other number) ... View more