ram pratap maurya <rampratap0000@xxxxxxxxx> writes: > we are planing to RHEL OS upgrade from 6.7 (Current version) to 8 version. > currently postgresql-12.6 version running on the server , we have upgraded > OS on test DB server from 6 to 8 version during OS upgrade > postgresql-12,11 and other package is removed and Postgresql is not > started. that why my DB is crashed , can you please suggest what is best > way to upgrade OS. There are a couple of big gotchas you need to think about: * RHEL8 is systemd based, while 6 still used the old initscript startup code. This means that the way to get a daemon process launched is completely different. So PG packages built for RHEL6 *will not work*. You need to get a server package that is systemd-ready, and that means one that was explicitly built for RHEL8. (Maybe a RHEL7 one would work, not sure. But it is zero surprise that the packages you listed aren't working.) * RHEL8 incorporates new locale data [1]. This means that non-English text is rather likely to sort differently than it did before, which in turn means that indexes on text columns will be corrupt if you try to upgrade in place. While you could REINDEX them after updating, this might be a good reason to do a dump-and-reload instead of trying to pg_upgrade. In short, this is no minor upgrade you're contemplating. regards, tom lane [1] https://wiki.postgresql.org/wiki/Locale_data_changes
