This sounds like bug 1429734. That effect on PostgreSQL was that after apt-get install postgresql-9.4 the cluster wasn't running if your system was in "degraded" mode, i. e. you had at least one failed unit. This was fixed yesterday.
Another possibility was the race condition fixed in https://launchpad.net/ubuntu/+source/postgresql-common/166bzr2 (stuck in proposed for a while, but should migrate in a few minutes now), which also caused postgresql@9.4-xxxx.service to not start up, while the "umbrella" postgresql.service was running (but that's just a no-op, and mostly just a dependency target). Can you please re-try with the current vivid versions and with p-common 166bzr2? ** Changed in: maas (Ubuntu) Status: Confirmed => Incomplete -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1430025 Title: maas uninstallable on vivid To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/maas/+bug/1430025/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs