MongoDB start errors

Question

I was following along a course and entered a command that was given

mongod --dbpath=data --bind_ip 127.0.0.1

In the past, I had used mongo and it had worked, but I'm sure I had never entered this command. Now when I try to launch mongo via terminal I get this error:

MongoDB shell version v4.4.0
connecting to: mongodb://127.0.0.1:27017/?compressors=disabled&gssapiServiceName=mongodb
Error: couldn't connect to server 127.0.0.1:27017, connection attempt failed: SocketException: Error connecting to 127.0.0.1:27017 :: caused by :: Connection refused :
connect@src/mongo/shell/mongo.js:362:17
@(connect):2:6
exception: connect failed
exiting with code 1

Whenever I try to start up mongod I get this error:

{"t":{"$date":"2020-08-24T10:50:51.683+02:00"},"s":"I",  "c":"CONTROL",  "id":23285,   "ctx":"main","msg":"Automatically disabling TLS 1.0, to force-enable TLS 1.0 specify --sslDisabledProtocols 'none'"}
{"t":{"$date":"2020-08-24T10:50:51.715+02:00"},"s":"W",  "c":"ASIO",     "id":22601,   "ctx":"main","msg":"No TransportLayer configured during NetworkInterface startup"}
{"t":{"$date":"2020-08-24T10:50:51.716+02:00"},"s":"I",  "c":"NETWORK",  "id":4648602, "ctx":"main","msg":"Implicit TCP FastOpen in use."}
{"t":{"$date":"2020-08-24T10:50:51.721+02:00"},"s":"I",  "c":"STORAGE",  "id":4615611, "ctx":"initandlisten","msg":"MongoDB starting","attr":{"pid":51965,"port":27017,"dbPath":"/data/db","architecture":"64-bit","host":"22biedermann-p"}}
{"t":{"$date":"2020-08-24T10:50:51.721+02:00"},"s":"I",  "c":"CONTROL",  "id":23403,   "ctx":"initandlisten","msg":"Build Info","attr":{"buildInfo":{"version":"4.4.0","gitVersion":"563487e100c4215e2dce98d0af2a6a5a2d67c5cf","modules":[],"allocator":"system","environment":{"distarch":"x86_64","target_arch":"x86_64"}}}}
{"t":{"$date":"2020-08-24T10:50:51.722+02:00"},"s":"I",  "c":"CONTROL",  "id":51765,   "ctx":"initandlisten","msg":"Operating System","attr":{"os":{"name":"Mac OS X","version":"18.7.0"}}}
{"t":{"$date":"2020-08-24T10:50:51.722+02:00"},"s":"I",  "c":"CONTROL",  "id":21951,   "ctx":"initandlisten","msg":"Options set by command line","attr":{"options":{}}}
{"t":{"$date":"2020-08-24T10:50:51.731+02:00"},"s":"E",  "c":"STORAGE",  "id":20557,   "ctx":"initandlisten","msg":"DBException in initAndListen, terminating","attr":{"error":"NonExistentPath: Data directory /data/db not found. Create the missing directory or specify another path using (1) the --dbpath command line option, or (2) by adding the 'storage.dbPath' option in the configuration file."}}
{"t":{"$date":"2020-08-24T10:50:51.732+02:00"},"s":"I",  "c":"NETWORK",  "id":20562,   "ctx":"initandlisten","msg":"Shutdown: going to close listening sockets"}
{"t":{"$date":"2020-08-24T10:50:51.732+02:00"},"s":"I",  "c":"-",        "id":20520,   "ctx":"initandlisten","msg":"Stopping further Flow Control ticket acquisitions."}
{"t":{"$date":"2020-08-24T10:50:51.733+02:00"},"s":"I",  "c":"CONTROL",  "id":20565,   "ctx":"initandlisten","msg":"Now exiting"}
{"t":{"$date":"2020-08-24T10:50:51.733+02:00"},"s":"I",  "c":"CONTROL",  "id":23138,   "ctx":"initandlisten","msg":"Shutting down","attr":{"exitCode":100}}

I have been googling and trying to find different solutions but I have no clue how to proceed. I am using Mac OS.

Answer 1

The reason it is failing is right there in the logs:

Data directory /data/db not found

If you start mongod with no dbPath parameter it will default to /data/db. On your system, if you have used MongoDB in the past it must have been with a different dbPath or you have since deleted that path. I suggest you either specify a different path or create the /data/db folder for MongoDB to store its data.

Answer 2

this worked for me:

sudo mkdir -p /data/db

sudo chmod 777 /data/db