Description of problem:
Asking systemd to start mongod fails.

Version-Release number of selected component (if applicable):
1.8.2
9.fc16

How reproducible:
Always

Steps to Reproduce:
1. Issue command systemctl start mongod.service
  
Actual results:
# systemctl start mongod.service
Job failed. See system logs and 'systemctl status' for details.
# systemctl status mongod.service
mongod.service - High-performance, schema-free document-oriented database
	  Loaded: loaded (/lib/systemd/system/mongod.service; enabled)
	  Active: failed since Fri, 27 Jan 2012 12:27:12 +0000; 37s ago
	 Process: 14479 ExecStart=/usr/bin/mongod $OPTIONS run (code=exited, status=255)
	  CGroup: name=systemd:/system/mongod.service

Expected results:
Mongod should start.

Additional info:
I can start the daemon manually by issuing the command:
/usr/bin/mongod --quiet -f /etc/mongodb.conf