Re: BUG #8612: Truncate did not release disk space

On Fri, Nov 22, 2013 at 11:12 AM, Stefan Kaltenbrunner <
stefan(at)kaltenbrunner(dot)cc> wrote:

> On 11/20/2013 08:35 PM, eduardoa(at)mirthcorp(dot)com wrote:
> > The following bug has been logged on the website:
> >
> > Bug reference: 8612
> > Logged by: Eduardo Armendariz
> > Email address: eduardoa(at)mirthcorp(dot)com
> > PostgreSQL version: 9.0.13
> > Operating system: CentOS
> > Description:
> >
> > Ran out of disk space and postgres shut down. Recovered enough disk space
> > for database to be operational. Truncated the largest table in the
> database,
> > the message table. This table had over 600gb of data. The result of the
> > truncate was that only about 200gb of the data was actually released to
> the
> > OS.
>
> sure that no other backend was/is actually still a file-handle
> referenced? That open filehandle will prevent the OS from showing up the
> freed space on the filesystem and can happen if you have backends still
> running that once referenced the table now truncated and have not done
> any work since you did the truncate (like a large connection pool or
> idle client connections, maybe an open psql session or something like
> that).
>

If that were the case, I don't think pg_database_size would still be
counting the size, as it would no longer be able to find it the files in
that directory.

I think the next step would be to get an 'ls -l' listing of the
$PGDATA/base/<dboid>
directory.

Cheers,

Jeff