Failed to unlink socket file [MongoDB]

Question

I am new to MongoDB & I am trying to install [email protected] to use mongo on Mac, I proceeded to all these steps by steps :

sudo brew install mongodb

mkdir -p /data/db

sudo chown -R -un' /data/db

mongo or mongod

until i got this on terminal :

{"t":{"$date":"2022-03-08T20:19:25.376+01:00"},"s":"I",  "c":"CONTROL",  "id":21951,   "ctx":"initandlisten","msg":"Options set by command line","attr":{"options":{}}}
{"t":{"$date":"2022-03-08T20:19:25.377+01:00"},"s":"E",  "c":"NETWORK",  "id":23024,   "ctx":"initandlisten","msg":"Failed to unlink socket file","attr":{"path":"/tmp/mongodb-27017.sock","error":"Permission denied"}}
{"t":{"$date":"2022-03-08T20:19:25.377+01:00"},"s":"F",  "c":"-",        "id":23091,   "ctx":"initandlisten","msg":"Fatal assertion","attr":{"msgid":40486,"file":"src/mongo/transport/transport_layer_asio.cpp","line":989}}
{"t":{"$date":"2022-03-08T20:19:25.377+01:00"},"s":"F",  "c":"-",        "id":23092,   "ctx":"initandlisten","msg":"\n\n***aborting after fassert() failure\n\n"}
mac@macs-MacBook-Pro ~ % mongod --dbpath ~/data/db
{"t":{"$date":"2022-03-08T20:21:23.974+01:00"},"s":"I",  "c":"CONTROL",  "id":23285,   "ctx":"thread1","msg":"Automatically disabling TLS 1.0, to force-enable TLS 1.0 specify --sslDisabledProtocols 'none'"}
{"t":{"$date":"2022-03-08T20:21:23.974+01:00"},"s":"I",  "c":"NETWORK",  "id":4915701, "ctx":"thread1","msg":"Initialized wire specification","attr":{"spec":{"incomingExternalClient":{"minWireVersion":0,"maxWireVersion":13},"incomingInternalClient":{"minWireVersion":0,"maxWireVersion":13},"outgoing":{"minWireVersion":0,"maxWireVersion":13},"isInternalClient":true}}}
{"t":{"$date":"2022-03-08T20:21:23.974+01:00"},"s":"W",  "c":"ASIO",     "id":22601,   "ctx":"thread1","msg":"No TransportLayer configured during NetworkInterface startup"}
{"t":{"$date":"2022-03-08T20:21:23.974+01:00"},"s":"I",  "c":"NETWORK",  "id":4648602, "ctx":"thread1","msg":"Implicit TCP FastOpen in use."}
{"t":{"$date":"2022-03-08T20:21:23.976+01:00"},"s":"W",  "c":"ASIO",     "id":22601,   "ctx":"thread1","msg":"No TransportLayer configured during NetworkInterface startup"}
{"t":{"$date":"2022-03-08T20:21:23.976+01:00"},"s":"I",  "c":"REPL",     "id":5123008, "ctx":"thread1","msg":"Successfully registered PrimaryOnlyService","attr":{"service":"TenantMigrationDonorService","ns":"config.tenantMigrationDonors"}}
{"t":{"$date":"2022-03-08T20:21:23.976+01:00"},"s":"I",  "c":"REPL",     "id":5123008, "ctx":"thread1","msg":"Successfully registered PrimaryOnlyService","attr":{"service":"TenantMigrationRecipientService","ns":"config.tenantMigrationRecipients"}}
{"t":{"$date":"2022-03-08T20:21:23.976+01:00"},"s":"I",  "c":"CONTROL",  "id":5945603, "ctx":"thread1","msg":"Multi threading initialized"}
{"t":{"$date":"2022-03-08T20:21:23.976+01:00"},"s":"I",  "c":"CONTROL",  "id":4615611, "ctx":"initandlisten","msg":"MongoDB starting","attr":{"pid":69610,"port":27017,"dbPath":"/Users/mac/data/db","architecture":"64-bit","host":"macs-MacBook-Pro.local"}}
{"t":{"$date":"2022-03-08T20:21:23.976+01:00"},"s":"I",  "c":"CONTROL",  "id":23403,   "ctx":"initandlisten","msg":"Build Info","attr":{"buildInfo":{"version":"5.0.6","gitVersion":"212a8dbb47f07427dae194a9c75baec1d81d9259","modules":[],"allocator":"system","environment":{"distarch":"x86_64","target_arch":"x86_64"}}}}
{"t":{"$date":"2022-03-08T20:21:23.976+01:00"},"s":"I",  "c":"CONTROL",  "id":51765,   "ctx":"initandlisten","msg":"Operating System","attr":{"os":{"name":"Mac OS X","version":"20.1.0"}}}
{"t":{"$date":"2022-03-08T20:21:23.976+01:00"},"s":"I",  "c":"CONTROL",  "id":21951,   "ctx":"initandlisten","msg":"Options set by command line","attr":{"options":{"storage":{"dbPath":"/Users/mac/data/db"}}}}
{"t":{"$date":"2022-03-08T20:21:23.977+01:00"},"s":"E",  "c":"NETWORK",  "id":23024,   "ctx":"initandlisten","msg":"Failed to unlink socket file","attr":{"path":"/tmp/mongodb-27017.sock","error":"Permission denied"}}
{"t":{"$date":"2022-03-08T20:21:23.977+01:00"},"s":"F",  "c":"-",        "id":23091,   "ctx":"initandlisten","msg":"Fatal assertion","attr":{"msgid":40486,"file":"src/mongo/transport/transport_layer_asio.cpp","line":989}}
{"t":{"$date":"2022-03-08T20:21:23.977+01:00"},"s":"F",  "c":"-",        "id":23092,   "ctx":"initandlisten","msg":"\n\n***aborting after fassert() failure\n\n"}```

Answer 1

Most probably you missed to shutdown properly your mongod previous time so there is socket file left in the tmp folder that you need to remove manually before you try to start the mongod process again:

    rm /tmp/mongodb-27017.sock