ORA-00449: background process 'MMAN' unexpectedly terminated with error 7446 One of our Oracle servers went down rather badly last night, and we have been unable to bring it online since. Attempting to startup each instance results in:

SQL&gt; Connected to an idle instance.
SQL&gt; ORA-00449: background process 'MMAN' unexpectedly terminated with error 7446
ORA-07446: sdnfy: bad value '' for parameter .
SQL&gt; Disconnected


After running this, none of the instances are online. The listener reports that is running, at least.

The first instance (asdb) in the order has a number of (mostly repetitive sections) in its alert.log, but nothing in there seems particularly likely. The other instances have blank (but writeable) alert.log files.

Where should I investigate to try and get this back online?
For some reason, it seems that the bdump and cdump directories for each instance had been deleted. I don't know who (or what) did that, but restoring them fixed the problem.