- reverted back to 9.4 - connected to each of the databases and checked postgis version: select distinct probin from pg_proc where probin IS NOT null order by probin
- i discovered i did not need databases with postgis-2.1 anyway (although template_postgis had to go too), so i dropped them - upgrade to 9.5 went fine
- pg_upgrade terminated with the following error: Could not load library "$libdir/postgis-2.2" ERROR: incompatible library "/usr/lib/postgresql/postgis-2.2.so": version mismatch DETAIL: Server is version 9.5, library is version 9.4.
- i upgraded postgis from 2.2.0 to 2.2.1 and ran pg_upgrade again.
this time it ended with a different error but now i am unable to proceed any further (no idea which way to take it from here): .. Checking for presence of required libraries fatal
Your installation references loadable libraries that are missing from the new installation. You can add these libraries to the new installation, or remove the functions using them from the old installation. A list of problem libraries is in the file: loadable_libraries.txt
Failure, exiting $ cat loadable_libraries.txt Could not load library "$libdir/postgis-2.2" ERROR: attempt to redefine parameter "postgis.backend"
oddly enough i can see postgis-2.2 in both 9.4 and the new installation: /opt/pgsql-9.4/lib/postgis-2.2.so /usr/lib/postgresql/postgis-2.2.so