Re: What does hdfs balancer do after adding more disks to existing datanode.

Hi, dfs data directory at a datanode stores blocks in following directory structure: All blocks are stored at location: /current/ This directory contains some blocks and some subdirectories named like 'subdir*' (eg. subdir0, subdir1, ... ,subdir33, ..,subdir63) To be precise, each directory in d

Re: What does hdfs balancer do after adding more disks to existing datanode.

Ajit, Just move/merge subdirectories - its the easiest way to go about it and does no harm. For confidence, you can also fire up a test cluster and test out these things :) On 05-Dec-2011, at 2:59 PM, Ajit Ratnaparkhi wrote: > Hi, > > dfs data directory at a datanode stores blocks in followin

RE: What does hdfs balancer do after adding more disks to existing datanode.

Hi, Current volume choosing policy is round robin fashion, Since the DN got new disk, balancer will balance some blocks to this node. But the volume choosing will be same when palcing the block. AFAIK, it wont do any special balancing between disks in the same node. please correct me if i under