Hello,
Few weeks ago our customer experienced some spikes on his Postgres 9.4.5 database. We've been alerted of a significant disk usage increase and pg_serial seemed to be the culprit.
We noticed a lot of those errors in the logs
" could not truncate directory "pg_serial": apparent wraparound "
No more errors now but the pg_serial is still 8G big and doesn't seem to decrease.
The only thing I could find related to this was an old bug from 2011 which might be fixed now.
We wonder what is responsible for cleaning up the old transactions in pg_serial and how it could dysfunction in this case.
Would you have any clue ?
Cheers,