[Pkg-postgresql-public] Bug#784005: Bug#784005: postgresql-9.4: Cluster upgrade from 9.1 to 9.4 results in broken configuration

[Gunnar Wolf]

Christoph Berg dijo [Thu, May 14, 2015 at 10:11:44PM +0200]:
> Hi Gunnar,
> 
> I'd call it a LXC bug if it doesn't support POSIX shared memory.
> That said, I've been bitten by this problem as well - in my case,
> /dev/shm was simply not mounted and a cluster with no explicit
> dynamic_shared_memory_type setting defaulted to "posix" didn't start.
> If you create a new cluster in such an environment, initdb will probe
> the various shared memory types and pick one that works. I'm not
> really happy with this auto-probing because it hides the real problem,
> but atm that's what upstream has designed.
> 
> We'll document the gotcha in README.Debian.

Hi!

I asked a PostgreSQL developer friend of mine, and he answered (in
Spanish, translation bugs are mine):

    Hmm, if I understand correctly, the problem is that the
    postgresql.conf is copied from the old server to the new one,
    right? I think that, by itself, is a bug... The configuration
    files are attempted to be kept reasonably compatible, but there is
    no promise that it will always work.

    Particularly, with parameters such as the shared memory type,
    initdb should take care of setting the right values.

    I think it's a pg_upgradecluster bug (which is part of the Debian
    packaging, not of Postgres)

I guess LXC does provide shared memory, but it might be that my
configuration does not allow it. I am newbie-ish on its specifics.

Greetings!