See "Copying between versions of HDFS": http://hadoop.apache.org/common/docs/r0.20.2/distcp.html#cpver
J-D On Fri, Apr 22, 2011 at 10:37 PM, Jonathan Disher <jdis...@parad.net> wrote: > I have an existing cluster running hadoop-0.20.1, and I am migrating most of > the data to a new cluster running -0.20.2. I am seeing this in the namenode > logs when I try to run a distcp: > > @400000004db263bf29c77134 WARN ipc.Server: Incorrect header or version > mismatch from newNN:46111 got version 4 expected version 3 > 2011-04-23 05:30:55,999 WARN org.apache.hadoop.ipc.Server: Incorrect header > or version mismatch from oldNN:48750 got version 3 expected version 4 > > When I run my distcp, on either side, it dies with a > java.io.IOException/java.io.EOFException. > > Ideas? Am I screwed? I really don't want to drop my new cluster down to > 0.20.1. > > -j
