Well, the response to the ticket was quite fast : https://status.online.net/index.php?do=details&task_id=720 Here's the stated cause : >Our tests have confirmed an issue caused by the fans of the power supplies installed in several chassis. >The fans create vibrations amplifying errors on the discs. Now on to decide whether I'm waiting for the fix or re-building a new box... Thanks a bunch for your help. -- Bien à vous, Vincent Veyron https://libremen.com Logiciels de gestion, libres -- Sent via pgsql-performance mailing list (pgsql-performance@xxxxxxxxxxxxxx) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-performance