I attempted an upgrade from 0.20.2 to 0.21.0 the other day and run into a bunch of major issues. Now I am attempting to roll back HDFS. I did not finalize the upgrade.
After I switched out the binaries on the install and reverted the configs back to my 0.20.2 version, I attempted to do ./start-dfs.sh -rollback but found the following error in the logs: ERROR org.apache.hadoop.hdfs.server.namenode.NameNode: java.io.IOException: Cannot rollback. None of the storage directories contain previous fs state. Looking inside the dfs.name.dir location I do see a previous.checkpoint directory. Inside the dfs.data.dir directory I also see a previous directory that still exists. When I try to load up ./start-dfs.sh without the -rollback I get: ERROR org.apache.hadoop.hdfs.server.namenode.NameNode: java.io.IOException: Unexpected version of the file system log file: -24. Current version = -18. Any suggestions on what I can try next ? I am desperate to get this back up and running. I spent 2 days fighting the 0.21.0 upgrade and would rather get back to something stable. The reason I attempted the upgrade was to solve some really strange issues with the fair scheduler. Thanks!
