Jaime Silvela <JSilvela@xxxxxxxx> writes: > The kernel is Linux 2.6.5 2.6.5.what (give us full uname -a output please)? On what hardware? If memory serves, we had some reason to think that it only occurred on specific 64-bit multi-CPU platforms, so I'm not just asking idly. The error check was put in as a consequence of this thread: http://archives.postgresql.org/pgsql-admin/2006-09/msg00250.php > So I take it that this happens on the restore part, not the dump part then? It's definitely a write failure not a read failure. Per the code comments: * We get here only in the corner case where we are trying to extend * the relation but we found a pre-existing buffer marked BM_VALID. * This can happen because mdread doesn't complain about reads beyond * EOF --- which is arguably bogus, but changing it seems tricky --- * and so a previous attempt to read a block just beyond EOF could * have left a "valid" zero-filled buffer. Unfortunately, we have * also seen this case occurring because of buggy Linux kernels that * sometimes return an lseek(SEEK_END) result that doesn't account for * a recent write. In that situation, the pre-existing buffer would * contain valid data that we don't want to overwrite. Since the * legitimate cases should always have left a zero-filled buffer, * complain if not PageIsNew. regards, tom lane
