首先依照官方文档的描述，创建了配置文件，修改了数据库路径，配置文件mongo.config内容如下所示：

systemLog:
    destination: file
    path: I:\mongodb_data\log\mongod.log
    logAppend: false
storage:
    dbPath: I:\mongodb_data\db
net:
   port: 27017
   bindIp: 127.0.0.1

然后定制了mongodb的服务，命令如下：

mongod --config "C:\\Program Files\\MongoDB\\Server\\3.6\\mongo.config" --install

然后重启了mongdb服务，但打开mongod后发现，数据库路径依然在C盘，如下：

C:\Program Files\MongoDB\Server\3.6\bin>mongod
2018-03-26T23:33:52.760-0700 I CONTROL  [initandlisten] MongoDB starting : pid=29408 port=27017 dbpath=C:\data\db\ 64-bit host=LAPTOP-5EHTU72R
2018-03-26T23:33:52.760-0700 I CONTROL  [initandlisten] targetMinOS: Windows 7/Windows Server 2008 R2
2018-03-26T23:33:52.761-0700 I CONTROL  [initandlisten] db version v3.6.3
2018-03-26T23:33:52.763-0700 I CONTROL  [initandlisten] git version: 9586e557d54ef70f9ca4b43c26892cd55257e1a5
2018-03-26T23:33:52.764-0700 I CONTROL  [initandlisten] OpenSSL version: OpenSSL 1.0.1u-fips  22 Sep 2016
2018-03-26T23:33:52.766-0700 I CONTROL  [initandlisten] allocator: tcmalloc
2018-03-26T23:33:52.767-0700 I CONTROL  [initandlisten] modules: none
2018-03-26T23:33:52.769-0700 I CONTROL  [initandlisten] build environment:
2018-03-26T23:33:52.771-0700 I CONTROL  [initandlisten]     distmod: 2008plus-ssl
2018-03-26T23:33:52.773-0700 I CONTROL  [initandlisten]     distarch: x86_64
2018-03-26T23:33:52.774-0700 I CONTROL  [initandlisten]     target_arch: x86_64
2018-03-26T23:33:52.776-0700 I CONTROL  [initandlisten] options: {}
2018-03-26T23:33:52.778-0700 I STORAGE  [initandlisten] exception in initAndListen: NonExistentPath: Data directory C:\data\db\ not found., terminating
2018-03-26T23:33:52.779-0700 I CONTROL  [initandlisten] now exiting
2018-03-26T23:33:52.782-0700 I CONTROL  [initandlisten] shutting down with code:100

请问为什么配置文件无效？我完全是按官方文档来做的啊