Bill, Thank you. Unfortunately, that will not work for us, as our hadoop-19 has long been finalized.
dbr On Wed, Mar 18, 2009 at 2:35 PM, Bill Au <bill.w...@gmail.com> wrote: > As long as the version upgrade has not been finalized, here's the procedure > I use to downgrade: > > > 1. make sure that the previous version upgrade has not been finalized. A > version upgrade cannot be rollback if it has been finalized. > > bin/hadoop dfsadmin -upgradeProgress status > > 2. stop map-reduce cluster. > > bin/stop-mapred.sh > > 3. stop all applications and make sure that there are no running tasks. > 4. stop HDFS cluster. > > bin/stop-dfs.sh > > 5. rollback version of Hadoop. Install previous version of Hadoop if > previous version of Hadoop has been removed from the system. > 6. start HDFS with the rollback option. > > bin/start-dfs.sh -rollback > > 7. monitor the rollback until it is complete. > > bin/hadoop dfsadmin -upgradeProgress status > > 8. start map-reduce cluster. > > bin/start-mapred.sh > > > > Bill > > On Wed, Mar 18, 2009 at 1:08 PM, David Ritch <david.ri...@gmail.com> > wrote: > > > There is an established procedure for upgrading from one release of > Hadoop > > to a newer release. Is there something similar to move back to an > > lower-numered release? > > > > Specifically, we have data in a cloud running Hadoop-19.0. Because of > > stability issues, we are wondering whether we should move back to 18, but > > we > > don't want to lose our data. Is there a downward migration path? > > > > Thanks, > > > > David > > >
