General developer forum

My thanks to Matteo and Renaat who responded to this post. We have not managed to work out precisely which processes had caused the file locking, but we have at least removed any file locks and set moodle back to using file locking. Our network admins are monitoring for the next few days to try to work out what, if anything, might be trying to do file locking; it was the advice on this forum that pointed us in the right direction.