Re: Odd db lockup - investigation advice wanted

Marc Munro <marc(at)bloodnok(dot)com> writes:

> PGDATA is installed on a Netapp network storage device.

This is generally not recommended--it should be on a local disk (SAN,
etc) rather than NFS.

> We are using slony 1.1.0 for replication.
>
> The (provider) database locked-up after I killed a slony client process
> (kill -9) on the subscriber. Psql connections would not respond to \d
> and simply locked up. I was able to run a query to check for blocking
> locks - this returned no rows. There was a significant test load on the
> database at the time.
>
> I stopped the database but was unable to restart it. I was unable to
> kill a number of postgres processes and could not release postgres
> shared memory. Having decided that the database was toast, I discovered
> that I could not even delete the database files, and eventually the only
> solution was a full reboot.

This sounds like you had kernel problems, not PG problems. Linux NFS
support is continually improving but still seems to have issues. I
would strongly recommend using local disk for your database storage.

-Doug