In Fedora >= 24 we already have PostgreSQL >= 9.5. In CentOS / RHEL PostgreSQL is available using software collections. We should be able to upgrade from 4.1 to 4.2 enabling PostgreSQL >= 9.5 as part of the update.
This scenarios should be tested: 1. fresh install 4.2, postgres 9.5 2. upgrade 4.1, postgres < 9.5 => 4.2, postgres 9.5 3. upgrade 4.2, postgres 9.5 => newer 4.2, postgres 9.5 4. fresh install 4.2, postgres 9.6 5. upgrade 4.1, postgres < 9.5 => 4.2, postgres 9.6 6. upgrade 4.2, postgres 9.5 => newer 4.2, postgres 9.6 Notice: 4.2 will work only with postgres >= 9.5 and so can't be installed with lower postgres versions.
(In reply to Lucie Leistnerova from comment #1) > This scenarios should be tested: We need also to consider that we have the engine, engine DB, DWH and DWH DB and all of them could be on the same machine or on 4 distinct machines in the worst case.
Scenarios from Comment 1 were tested for: - dwh, engine both service and db locally - dwh, engine service locally, dwh, engine's db remotely - engine both service and db locally, dwh both service and db remotely Some errors occurred, see depending BZ. It all should be fixed now, so engine is working well with postgres 9.5 and 9.6 in main functions.
This bugzilla is included in oVirt 4.2.0 release, published on Dec 20th 2017. Since the problem described in this bug report should be resolved in oVirt 4.2.0 release, published on Dec 20th 2017, it has been closed with a resolution of CURRENT RELEASE. If the solution does not work for you, please open a new bug report.