Hello, I'm trying to nail down a process for converting existing Apache-hadoop clusters with significant amounts of pre-existing data to CDH3. While I've found documentation for upgrading between CDH versions, I haven't seen one for standard Apache-hadoop => CDH3 with the "new" mapred and hdfs users and groups. I'm looking for the proper method to manually convert permissions on existing data from a single user&group setup (hadoop/hadoop) to the 2user & 3 group setup of hdfs/mapred users with hdfs/mapred/hadoop groups.
What I'm thinking needs to happen is something like this: 1. Shutdown cluster. 2. Perform full configuration and HDFS data backup. 3. Delete existing hadoop user/group while leaving HDFS data/mapred folders untouched. 4. Install CDH3 packages (which sets up new users and groups). 5. Manually adjust permissions/groups/ownership of old data files to match new CDH3 security setup. 6. Flow into standard hadoop-upgrade process. Basically, I'm trying to nail down setup 5, and would appreciate any guidance on this. I'm guessing I just haven't found the correct document since this seems like it would be a common endeavor. Thanks in advance, -JR
