M, See http://wiki.apache.org/hadoop/FAQ - "3.6. I want to make a large cluster smaller by taking out a bunch of nodes simultaneously. How can this be done?"
This explains how to decomission nodes by moving the data off of the existing node. It's fairly easy and painless (just add the nodename to the slaves.exclude file and notify dfs) and once the data is off the node you could swap-out the disks and then re-introduce the node back into the cluster with larger drives (removing the nodename from slaves.exclude). Chris On 17 May 2012 02:55, Mayuran Yogarajah <mayuran.yogara...@casalemedia.com>wrote: > Our cluster has several nodes which have smaller disks than other nodes and > as a result fill up quicker. > > I am looking to move data off these nodes and onto the others. > > > > Here is what I am planning to do: > > 1) On the nodes with smaller disks, set dfs.datanode.du.reserved to a > larger value > > 2) Restart data nodes > > 3) Run balancer > > > > Will this have the desired effect? > > If there is a better way to accomplish this please let me know. > > > > Thanks, > > M > >
