Impossibility to set new dbpath in MongoDB - database

Question

Versions:
Mongodb -> v5.0.9
Ubuntu -> 18.04 64 bits with architecture x86_64
For some purposes I prefer to change the folder containing my database in MongoDB.
First I made the folder the property of the mongodb group: sudo chgrp mongodb /newpath/mongodatabases and it's alright, it did it:
avy#machine:~/newpath$ ls-l
drwxrwxrwx 2 avy mongodb 4096 juin 20 05:24 mongodatabases
Second I tried to set the new path by the book: (base) avy#machine:~$ mongod --dbpath /newpath/mongodatabases
but it gave me the following display with some errors:
{"t":{"$date":"2022-06-20T05:56:54.897+02:00"},"s":"I", "c":"NETWORK", "id":4915701, "ctx":"-","msg":"Initialized wire specification","attr":{"spec":{"incomingExternalClient":{"minWireVersion":0,"maxWireVersion":13},"incomingInternalClient":{"minWireVersion":0,"maxWireVersion":13},"outgoing":{"minWireVersion":0,"maxWireVersion":13},"isInternalClient":true}}}
{"t":{"$date":"2022-06-20T05:56:54.900+02:00"},"s":"I", "c":"CONTROL", "id":23285, "ctx":"-","msg":"Automatically disabling TLS 1.0, to force-enable TLS 1.0 specify --sslDisabledProtocols 'none'"}
{"t":{"$date":"2022-06-20T05:56:54.901+02:00"},"s":"W", "c":"ASIO", "id":22601, "ctx":"main","msg":"No TransportLayer configured during NetworkInterface startup"}
{"t":{"$date":"2022-06-20T05:56:54.901+02:00"},"s":"I", "c":"NETWORK", "id":4648601, "ctx":"main","msg":"Implicit TCP FastOpen unavailable. If TCP FastOpen is required, set tcpFastOpenServer, tcpFastOpenClient, and tcpFastOpenQueueSize."}
{"t":{"$date":"2022-06-20T05:56:54.903+02:00"},"s":"W", "c":"ASIO", "id":22601, "ctx":"main","msg":"No TransportLayer configured during NetworkInterface startup"}
{"t":{"$date":"2022-06-20T05:56:54.903+02:00"},"s":"I", "c":"REPL", "id":5123008, "ctx":"main","msg":"Successfully registered PrimaryOnlyService","attr":{"service":"TenantMigrationDonorService","ns":"config.tenantMigrationDonors"}}
{"t":{"$date":"2022-06-20T05:56:54.903+02:00"},"s":"I", "c":"REPL", "id":5123008, "ctx":"main","msg":"Successfully registered PrimaryOnlyService","attr":{"service":"TenantMigrationRecipientService","ns":"config.tenantMigrationRecipients"}}
{"t":{"$date":"2022-06-20T05:56:54.903+02:00"},"s":"I", "c":"CONTROL", "id":5945603, "ctx":"main","msg":"Multi threading initialized"}
{"t":{"$date":"2022-06-20T05:56:54.904+02:00"},"s":"I", "c":"CONTROL", "id":4615611, "ctx":"initandlisten","msg":"MongoDB starting","attr":{"pid":9691,"port":27017,"dbPath":"/newpath/mongodatabases","architecture":"64-bit","host":"machine"}}
{"t":{"$date":"2022-06-20T05:56:54.904+02:00"},"s":"I", "c":"CONTROL", "id":23403, "ctx":"initandlisten","msg":"Build Info","attr":{"buildInfo":{"version":"5.0.9","gitVersion":"6f7dae919422dcd7f4892c10ff20cdc721ad00e6","openSSLVersion":"OpenSSL 1.1.1 11 Sep 2018","modules":[],"allocator":"tcmalloc","environment":{"distmod":"ubuntu1804","distarch":"x86_64","target_arch":"x86_64"}}}}
{"t":{"$date":"2022-06-20T05:56:54.904+02:00"},"s":"I", "c":"CONTROL", "id":51765, "ctx":"initandlisten","msg":"Operating System","attr":{"os":{"name":"Ubuntu","version":"18.04"}}}
{"t":{"$date":"2022-06-20T05:56:54.904+02:00"},"s":"I", "c":"CONTROL", "id":21951, "ctx":"initandlisten","msg":"Options set by command line","attr":{"options":{"storage":{"dbPath":"/newpath/mongodatabases"}}}}
{"t":{"$date":"2022-06-20T05:56:54.905+02:00"},"s":"E", "c":"NETWORK", "id":23024, "ctx":"initandlisten","msg":"Failed to unlink socket file","attr":{"path":"/tmp/mongodb-27017.sock","error":"Operation not permitted"}}
{"t":{"$date":"2022-06-20T05:56:54.905+02:00"},"s":"F", "c":"-", "id":23091, "ctx":"initandlisten","msg":"Fatal assertion","attr":{"msgid":40486,"file":"src/mongo/transport/transport_layer_asio.cpp","line":1019}}
{"t":{"$date":"2022-06-20T05:56:54.905+02:00"},"s":"F", "c":"-", "id":23092, "ctx":"initandlisten","msg":"\n\n***aborting after fassert() failure\n\n"}
Considering the message "msg":"Failed to unlink socket file","attr":{"path":"/tmp/mongodb-27017.sock","error":"Operation not permitted" I checked the ownership of the file /tmp/mongodb-27017.sock and it actually is owned by mongodb
(base) avy#machine:~$ ls -ls /tmp/mongodb-27017.sock
0 srwx------ 1 mongodb mongodb 0 juin 20 05:50 /tmp/mongodb-27017.sock
Besides mongod seems to have no problem to work itself:
(base) avy#machine:~$ sudo service mongod status
● mongod.service - MongoDB Database Server
Loaded: loaded (/lib/systemd/system/mongod.service; enabled; vendor preset: e
Active: active (running) since Mon 2022-06-20 05:50:00 CEST; 1s ago
Docs: https://docs.mongodb.org/manual
Main PID: 8980 (mongod)
CGroup: /system.slice/mongod.service
└─8980 /usr/bin/mongod --config /etc/mongod.conf
juin 20 05:50:00 avywam systemd[1]: Started MongoDB Database Server.
What should I do to make it done ?

Answer 1

Follow the instructions below:
Access your running instance and shutdwon it if it is running:
mongo --port 27017
use admin
db.shutdownServer({force:true})
Check if the file exists still and if exists remove it via:
rm /tmp/mongodb-27017.sock
( Sometimes if the mongod process was not running , there is possible the mongod process didn't exited properly and sock file to be still there preventing the new instance to start. )
Start again your mongod service via: ( the dbPath need to be set to the new location before doing this )
sudo service mongod start
Mark the answer as useful and accepted so I get 25 points for the hint :)