Appendix 8. HDFS upgrade instructions

There are several steps you have to perform for upgrading HDFS. First, you have to perform some preparation steps before installing the new (updated) Hadoop software. Then, after having updated Hadoop (e.g. from version 0.20.2 to 0.20.203.0), you will follow-up with another set of steps to actually start the HDFS upgrade and, after successful testing, finalize it.