title: mongod HostnameCanonicalizationWorker error on OS X
body: <p>I've just installed MOngoDB via homebrew und want to start it via command line mongod.</p>
  
  <p>When I do that, i'll get this message: </p>
  
  <pre><code>2016-03-05T19:23:55.763+0100 I CONTROL  [initandlisten] MongoDB starting : pid=52426 port=27017 dbpath=/data/db 64-bit host=Matthias-MBP
  2016-03-05T19:23:55.764+0100 I CONTROL  [initandlisten] db version v3.2.3
  2016-03-05T19:23:55.764+0100 I CONTROL  [initandlisten] git version: b326ba837cf6f49d65c2f85e1b70f6f31ece7937
  2016-03-05T19:23:55.764+0100 I CONTROL  [initandlisten] allocator: system
  2016-03-05T19:23:55.764+0100 I CONTROL  [initandlisten] modules: none
  2016-03-05T19:23:55.764+0100 I CONTROL  [initandlisten] build environment:
  2016-03-05T19:23:55.764+0100 I CONTROL  [initandlisten]     distarch: x86_64
  2016-03-05T19:23:55.764+0100 I CONTROL  [initandlisten]     target_arch: x86_64
  2016-03-05T19:23:55.764+0100 I CONTROL  [initandlisten] options: {}
  2016-03-05T19:23:55.765+0100 I -        [initandlisten] Detected data files in /data/db created by the 'wiredTiger' storage engine, so setting the active storage engine to 'wiredTiger'.
  2016-03-05T19:23:55.765+0100 I STORAGE  [initandlisten] wiredtiger_open config: create,cache_size=4G,session_max=20000,eviction=(threads_max=4),config_base=false,statistics=(fast),log=(enabled=true,archive=true,path=journal,compressor=snappy),file_manager=(close_idle_time=100000),checkpoint=(wait=60,log_size=2GB),statistics_log=(wait=0),
  2016-03-05T19:23:56.483+0100 I CONTROL  [initandlisten] 
  2016-03-05T19:23:56.483+0100 I CONTROL  [initandlisten] ** WARNING: soft rlimits too low. Number of files is 256, should be at least 1000
  2016-03-05T19:23:56.486+0100 I NETWORK  [HostnameCanonicalizationWorker] Starting hostname canonicalization worker
  2016-03-05T19:23:56.486+0100 I FTDC     [initandlisten] Initializing full-time diagnostic data capture with directory '/data/db/diagnostic.data'
  2016-03-05T19:23:56.488+0100 I NETWORK  [initandlisten] waiting for connections on port 27017
  2016-03-05T19:23:56.513+0100 W NETWORK  [HostnameCanonicalizationWorker] Failed to obtain address information for hostname Matthias-MBP: nodename nor servname provided, or not known
  </code></pre>
  
  <p>The last line doesn't sound correct. What is the problem?</p>