We had the disk with the directory database files fill up overnight, a rogue process :-[

Now the directory server will not start I get the following reported in the system logs.

Jul 29 09:44:50 bastion ns-slapd: auxpropfunc error invalid parameter supplied
Jul 29 09:44:50 bastion ns-slapd: sql_select option missing
Jul 29 09:44:50 bastion ns-slapd: auxpropfunc error no mechanism available

What can I do to recover the database so that I can start the server?