I have upgraded my test ES cluster from 2.3 to 5.6 (on my way to 6.0) and got myself into a pickle
I have now found some very old indexes from 1.5 that can not be upgraded, and this is fine because I don't want them anyway. However I can not see how to delete them and because the new 5.6 cluster won't start I am in a bit of a catch 22.
I really don' t want to downgrade it all just to delete the old indexes - it has taken me a long time to sort out my yml file for 5.6!
Any ideas on how to just remove the old obsolete indexes without re-installing?