currently we have 5 data nodes managed by Cloudera Manager Enterprise. Each data node has 12 disks used for HDFS. We now want to remove one disk on all data nodes to be used by the operating system and therefore excluded by HDFS completely. So the goal would be to have 11 instead of 12 disks in HDFS on each data node.
I found a documentation describing disk hot swapping for data nodes: http://www.cloudera.com/documentation/enterprise/latest/topics/admin_dn_swap.html
However I cannot find a documenation how to permanently remove a disk from all data nodes.
What steps are necessary to permanently remove a disk? Any ideas how to do this without having data loss or downtime?
What happens when I do this on all Data Nodes (lets say remove the mount point for drive 12).
What happens with the data stored on this mount points? Does Cloudera automatically do a rebelancing of the data?