@hadoopNoob,   In order to address this issue, you will need to free up space in /run/cloudera-scm-agent/process.   To do so, we need to know much space each process directorty is taking and also how old they are. You can try listing the directories in order of size with a command like:   du -h --max-depth=1 /run/cloudera-scm-agent/process | sort -h   It is OK to delete directories in /run/cloudera-scm-agent/process provided that process directory is not used for a running process.   /run/cloudera-scm-agent/process is where the configuration for any role you are starting resides, so if you run out of space, you will not be able to start processes on that host.     ... View more

@manuroman   I rebooted the 3 datanodes, now it is clear.   Thank you! ... View more

Hi @OFRPRANDERIA   First, putting an entity into maintenance mode only suppresses the alerts that those events would otherwise generate. You can see a history of all the events that were recorded for entities during the period that those entities were in maintenance mode.   Only if you have higher-level entity or priority services put those in maintenance mode.   If not, I recommended you to stop the service and then restart.   Regards, Manu. ... View more