Blocks already written to HDFS will remain their current size. Blocks are immutable objects. That procedure would set the size used for all subsequently-written blocks. I don't think you can change the block size while the cluster is running, because that would require the NameNode and DataNodes to re-read their configurations, which they only do at startup. - Aaron
On Sun, Apr 12, 2009 at 6:08 AM, Rakhi Khatwani <rakhi.khatw...@gmail.com>wrote: > Hi, > I would like to know if it is feasbile to change the blocksize of Hadoop > while map reduce jobs are executing? and if not would the following work? > 1. > stop map-reduce 2. stop-hbase 3. stop hadoop 4. change hadoop-sites.xml > to reduce the blocksize 5. restart all > whether the data in the hbase tables will be safe and automatically split > after changing the block size of hadoop?? > > Thanks, > Raakhi >
