Re: could not truncate directory "pg_subtrans": apparent wraparound

On Sat, Jun 6, 2015 at 9:45 AM, Dan Langille <dan@langille.org> wrote:
> I noticed this today on my 9.4.2 server running on FreeBSD 10.1:
>
> Jun  5 18:59:40 slocum postgres[986]: [3957-1] LOG:  could not truncate directory "pg_subtrans": apparent wraparound
>
> Looking at a post from 2010, Tom Lane suggest this information was useful:
>
> [root@slocum:/usr/local/pgsql/data/pg_subtrans] # ls -l
> total 1
> -rw-------  1 pgsql  pgsql  8192 Jun  5 19:04 0032
>
> This not not a high throughput server.

It looks like subtrantransactions may have a fencepost error similar
to multixacts, described here:

http://www.postgresql.org/message-id/CAEepm=0DqAtnM=23OQ44BbnwvN3g6+DXx+s5g4JRBP-VY8gEwQ@mail.gmail.com

I will try to repro this.

-- 
Thomas Munro
http://www.enterprisedb.com