mongodb真的很脆弱，公司加个防火墙，马上就不行了，撤掉也必须重启，重启还容易报错
cd 到mongodb的安装路径 ，然后启动
./mongod --dbpath=/data/mongodb/master/data --logpath=/data/mongodb/master/log/master.log data和log是两个文件夹，这里可以随意建
启动有异常信息
2017-08-31T17:25:31.926+0800 I CONTROL [initandlisten] MongoDB starting : pid=12882 port=27017 dbpath=/data/db 64-bit host=env-12
2017-08-31T17:25:31.926+0800 I CONTROL [initandlisten] db version v3.4.1
2017-08-31T17:25:31.926+0800 I CONTROL [initandlisten] git version: 5e103c4f5583e2566a45d740225dc250baacfbd7
2017-08-31T17:25:31.926+0800 I CONTROL [initandlisten] OpenSSL version: OpenSSL 1.0.1e-fips 11 Feb 2013
2017-08-31T17:25:31.926+0800 I CONTROL [initandlisten] allocator: tcmalloc
2017-08-31T17:25:31.926+0800 I CONTROL [initandlisten] modules: none
2017-08-31T17:25:31.926+0800 I CONTROL [initandlisten] build environment:
2017-08-31T17:25:31.926+0800 I CONTROL [initandlisten] distmod: rhel70
2017-08-31T17:25:31.926+0800 I CONTROL [initandlisten] distarch: x86_64
2017-08-31T17:25:31.926+0800 I CONTROL [initandlisten] target_arch: x86_64
2017-08-31T17:25:31.926+0800 I CONTROL [initandlisten] options: {}
2017-08-31T17:25:31.926+0800 I STORAGE [initandlisten] exception in initAndListen: 29 Data directory /data/db not found., terminating
2017-08-31T17:25:31.926+0800 I NETWORK [initandlisten] shutdown: going to close listening sockets...
2017-08-31T17:25:31.926+0800 I NETWORK [initandlisten] shutdown: going to flush diaglog...
2017-08-31T17:25:31.926+0800 I CONTROL [initandlisten] now exiting
2017-08-31T17:25:31.926+0800 I CONTROL [initandlisten] shutting down with code:100
解决办法：
把data目录下的.lock文件删掉，再执行启动命令，然后 ss -nlpt|grep mongo 能看到pid，说明启动成功了