当我开始mongod trowed错误.问题是什么？
root@cs12867:~# mongod
mongod --help for help and startup options
Sun Dec 22 15:37:44.081 [initandlisten] MongoDB starting : pid=18415 port=27017 dbpath=/data/db/ 64-bit host=cs12867
Sun Dec 22 15:37:44.081 [initandlisten] db version v2.4.6
Sun Dec 22 15:37:44.081 [initandlisten] git version: b9925db5eac369d77a3a5f5d98a145eaaacd9673
Sun Dec 22 15:37:44.081 [initandlisten] build info: Linux ip-10-2-29-40 2.6.21.7-2.ec2.v1.2.fc8xen #1 SMP Fri Nov 20 17:48:28 EST 2009 x86_64 BOOST_LIB_VERSION=1_49
Sun Dec 22 15:37:44.081 [initandlisten] allocator: tcmalloc
Sun Dec 22 15:37:44.081 [initandlisten] options: {}
Sun Dec 22 15:37:44.081 [initandlisten] exception …