So, I went for it and here are the answers (I found for myself) ...   Having successfully upgraded to Parcels (so claims the CM UI), can I now remove all 110 CDH5 RPM from those six servers? YES. You can remove all RPMs except the ones named cloudera-manager-*.rpm. Those are still needed to start CM and manage the cluster. Very Good. Will doing so remove critical configurations in /etc/<service-type>/conf (and configurations elsewhere)? NO. Everything was preserved and still consulted by the Parcel-converted Cloudera Manager. Very Good.   What about the Unix start/stop scripts, chkconfig-on configurations, etc? Will they be removed or affected? If yes, did the Parcel upgrade install its own version of these entries? BECAUSE, above, the 'cloudera-manager-*.rpm's were not removed, all Unix start/stop scrpts, chkconfig configurations, etc. were unaffected. Those RPM are what manage those items, and they were not removed. Very Good.   So everything went well. There will always be some post conversion prodding and tweaking to get things totally clean and plumbed -- and this instance was no different -- but overall things went pretty well.   I hope this helps others. =:)   ... View more

I ended up repairing the issue after more work.   The UI eventually revealed to me that the version of CDH (5.10) and CM (5.4) were not in sync. When I investigated why, I found that the entry in /etc/yum.repos.d/cloudera-manager.repo was pegged at  CDH 5.4, so my 'yum updates' did not update CM (though it updated everything else). So that made sense.   I updated the repo file, yum updated CM, and restarted. Then I let the UI walk me through a few upgrades and corrections of stale states. So I unfortunately don't know where the fix came. =:) But basically we can say that classpath.txt hadn't been updated properly. Now it has the correct entries.   I'm glad I didn't brute-force things (not my style anyway). I doubt this one-off issue will help anyone, but who knows. =:) ... View more