uhoo@ubuntu-mongo2:~$ sudo mongod
2015-12-23T16:33:00.057+0800 I JOURNAL [initandlisten] journal dir=/data/db/journal
2015-12-23T16:33:00.058+0800 I JOURNAL [initandlisten] recover : no journal files present, no recovery needed
2015-12-23T16:33:00.058+0800 I JOURNAL [initandlisten]
2015-12-23T16:33:00.058+0800 E JOURNAL [initandlisten] Insufficient free space for journal files
2015-12-23T16:33:00.058+0800 I JOURNAL [initandlisten] Please make at least 3379MB available in /data/db/journal or use --smallfiles
2015-12-23T16:33:00.058+0800 I JOURNAL [initandlisten]
2015-12-23T16:33:00.058+0800 I STORAGE [initandlisten] exception in initAndListen: 15926 Insufficient free space for journals, terminating
2015-12-23T16:33:00.059+0800 I CONTROL [initandlisten] now exiting
2015-12-23T16:33:00.059+0800 I NETWORK [initandlisten] shutdown: going to close listening sockets...
2015-12-23T16:33:00.059+0800 I NETWORK [initandlisten] removing socket file: /tmp/mongodb-27017.sock
2015-12-23T16:33:00.059+0800 I NETWORK [initandlisten] shutdown: going to flush diaglog...
2015-12-23T16:33:00.059+0800 I NETWORK [initandlisten] shutdown: going to close sockets...
2015-12-23T16:33:00.059+0800 I STORAGE [initandlisten] shutdown: waiting for fs preallocator...
2015-12-23T16:33:00.059+0800 I STORAGE [initandlisten] shutdown: final commit...
2015-12-23T16:33:00.059+0800 I STORAGE [initandlisten] shutdown: closing all files...
2015-12-23T16:33:00.059+0800 I STORAGE [initandlisten] closeAllFiles() finished
2015-12-23T16:33:00.059+0800 I CONTROL [initandlisten] dbexit: rc: 100

uhoo@ubuntu-mongo2:~$ sudo mongod --repair
2015-12-23T16:36:51.342+0800 I CONTROL [initandlisten] MongoDB starting : pid=1274 port=27017 dbpath=/data/db 64-bit host=ubuntu-mongo2
2015-12-23T16:36:51.343+0800 I CONTROL [initandlisten] ** WARNING: You are running this process as the root user, which is not recommended.
2015-12-23T16:36:51.343+0800 I CONTROL [initandlisten]
2015-12-23T16:36:51.343+0800 I CONTROL [initandlisten] db version v3.0.7
2015-12-23T16:36:51.343+0800 I CONTROL [initandlisten] git version: 6ce7cbe8c6b899552dadd907604559806aa2e9bd
2015-12-23T16:36:51.343+0800 I CONTROL [initandlisten] build info: Linux ip-10-229-88-125 3.13.0-24-generic #46-Ubuntu SMP Thu Apr 10 19:11:08 UTC 2014 x86_64 BOOST_LIB_VERSION=1_49
2015-12-23T16:36:51.343+0800 I CONTROL [initandlisten] allocator: tcmalloc
2015-12-23T16:36:51.343+0800 I CONTROL [initandlisten] options:

2015-12-23T16:36:51.344+0800 I STORAGE [initandlisten] repairDatabase mong
2015-12-23T16:36:51.344+0800 I - [initandlisten] Fatal assertion 18506 OutOfDiskSpace Cannot repair database mong having size: 83886080 (bytes) because free disk space is: 0 (bytes)
2015-12-23T16:36:51.376+0800 I CONTROL [initandlisten]
0xf5c3e9 0xefb231 0xee1aba 0x808d11 0x7d6db9 0x7f255889fec5 0x806677