I use pg_dump for my primary backup, once every three hours. I also use monit. When monit checks if PostgreSQL is alive during the pg_dump run, it sometimes times out, and restarts postgres. This results in failed backup.
What to do? Move to Write-Ahead-Logs? Disable monit during the backup? The database is serving an active web site at these times.
check process postgres with pidfile /usr/local/pgsql/data/postmaster.pid group database start program = "/etc/init.d/postgresql start" stop program = "/etc/init.d/postgresql stop" if failed unixsocket /tmp/.s.PGSQL.5432 protocol pgsql then restart if failed host 127.0.0.1 port 5432 protocol pgsql then restart if 5 restarts within 5 cycles then timeout