Where on /volume1/ should those dumps exactly be situated? If on the root level, than no, there are no dumps. Otherwise you’re right, the DS1813+ is a Cedarview model but still does not like to cooperate with DSM6 (had to be stopped before the upgrade, could not be executed afterwards, even after re-downloading and installing it).
But hold on, I just rebooted our Synology again (as two attached DX513 were not accessible) – and Sync COULD BE STARTED like before! So my apologies for the troubling message as it was clearly related to a side effect from the upgrade.
Sigh, too many updates/upgrades nowadays …