I used these instructions to install mongodb on my OS X machine. I did not make the files owned by root though, I used my local user (markdsievers), and installed to /usr/local/mongodb and usr/local/mongodb_data. I've chmod'ed and chown'ed all files and subdirectories of those to rwxrwxr-x  markdsievers  staff.
As user markdsievers I can start up the database without error using:
$ sudo mongod --dbpath=/usr/local/mongodb_data
However, if I start it with:
$ mongod --dbpath=/usr/local/mongodb_data/
I get:
Unable to create / open lock file for lockfilepath: /usr/local/mongodb_data/mongod.lock errno:13 Permission denied
What am I missing here?
/usr/local/mongodb_dataitself must be writable by the user runningmongod. Is it?drwxrwxr-x 8 markdsievers staff 272 11 Jul 06:30 mongodbdrwxrwxrwx 6 markdsievers staff 204 11 Jul 06:55 mongodb_data