default allocation of the MongoDB journal files

[Aelentel]

depending on the machine or virtual machine, it's possible to hit a filesystem free space problem.

it seems a bit overkill for this to necessitate 3.5 GB of free disk space.

/bin/sh -c "mongod" "--config" "/etc/oplog.config"
2016-11-21T16:40:44.908+0000 [initandlisten] MongoDB starting : pid=8 port=27017 dbpath=/data/db 64-bit host=db72986fa079
2016-11-21T16:40:44.908+0000 [initandlisten] db version v2.6.9
2016-11-21T16:40:44.908+0000 [initandlisten] git version: df313bc75aa94d192330cb92756fc486ea604e64
2016-11-21T16:40:44.908+0000 [initandlisten] build info: Linux build20.nj1.10gen.cc 2.6.32-431.3.1.el6.x86_64 #1 SMP Fri Jan 3 21:39:27 UTC 2014 x86_64 BOOST_LIB_VERSION=1_49
2016-11-21T16:40:44.908+0000 [initandlisten] allocator: tcmalloc
2016-11-21T16:40:44.908+0000 [initandlisten] options: { config: "/etc/oplog.config", replication: { replSet: "oplog" } }
2016-11-21T16:40:44.911+0000 [initandlisten] journal dir=/data/db/journal
2016-11-21T16:40:44.911+0000 [initandlisten] recover : no journal files present, no recovery needed
2016-11-21T16:40:44.911+0000 [initandlisten] 
2016-11-21T16:40:44.911+0000 [initandlisten] ERROR: Insufficient free space for journal files
2016-11-21T16:40:44.911+0000 [initandlisten] Please make at least 3379MB available in /data/db/journal or use --smallfiles
2016-11-21T16:40:44.911+0000 [initandlisten] 
2016-11-21T16:40:44.911+0000 [initandlisten] exception in initAndListen: 15926 Insufficient free space for journals, terminating
2016-11-21T16:40:44.912+0000 [initandlisten] dbexit: