运行“mongod”时，我得到以下内容：
mongod --help for help and startup options
2015-01-05T09:48:03.865-0800 [initandlisten] MongoDB starting : pid=1404 port=27017 dbpath=/data/db 64-bit host=Rahuls-MacBook-Pro.local
2015-01-05T09:48:03.865-0800 [initandlisten] db version v2.6.6
2015-01-05T09:48:03.865-0800 [initandlisten] git version: nogitversion
2015-01-05T09:48:03.865-0800 [initandlisten] build info: Darwin miniyosemite.local 14.0.0 Darwin Kernel Version 14.0.0: Fri Sep 19 00:26:44 PDT 2014; root:xnu-2782.1.97~2/RELEASE_X86_64 x86_64 BOOST_LIB_VERSION=1_49
2015-01-05T09:48:03.865-0800 [initandlisten] allocator: tcmalloc
2015-01-05T09:48:03.865-0800 [initandlisten] options: {}
2015-01-05T09:48:03.865-0800 [initandlisten] exception in initAndListen: 10296
*********************************************************************
ERROR: dbpath (/data/db) does not exist.
Create this directory or give existing directory in --dbpath.
See http://dochub.mongodb.org/core/startingandstoppingmongo
*********************************************************************
, terminating
2015-01-05T09:48:03.865-0800 [initandlisten] dbexit:
2015-01-05T09:48:03.865-0800 [initandlisten] shutdown: going to close listening sockets...
2015-01-05T09:48:03.865-0800 [initandlisten] shutdown: going to flush diaglog...
2015-01-05T09:48:03.865-0800 [initandlisten] shutdown: going to close sockets...
2015-01-05T09:48:03.865-0800 [initandlisten] shutdown: waiting for fs preallocator...
2015-01-05T09:48:03.865-0800 [initandlisten] shutdown: lock for final commit...
2015-01-05T09:48:03.866-0800 [initandlisten] shutdown: final commit...
2015-01-05T09:48:03.866-0800 [initandlisten] shutdown: closing all files...
2015-01-05T09:48:03.866-0800 [initandlisten] closeAllFiles() finished
2015-01-05T09:48:03.866-0800 [initandlisten] dbexit: really exiting now
我知道这是一个路径错误但是如何设置路径以便服务器启动？