Why my mongodb docker not writing data to host folder using volume? - mongodb

Question

I want to know why my mongo docker not writing data to local foler. I run my mongo docker with this command:
(/data/db seems to be the mongdo docker's data storage position, and /data/docker/mongo_volume is the folder in the "host" machine)
sudo docker run -it -v /data/db:/data/docker/mongo_volume -d mongo
When the mongo docker successfully started in my host , $docker ps looks like good:
u#VM-0-9-ubuntu:/data/docker/mongo_volume$ sudo docker ps
CONTAINER ID IMAGE COMMAND CREATED STATUS PORTS NAMES
5848da7562a3 mongo "docker-entrypoint.s…" 10 minutes ago Up 10 minutes 0.0.0.0:27017->27017/tcp, :::27017->27017/tcp sleepy_clarke
and $ docker inspect <container_id> shows the mounted volume:
"Mounts": [
{
"Type": "bind",
"Source": "/data/db",
"Destination": "/data/docker/mongo_volume",
"Mode": "",
"RW": true,
"Propagation": "rprivate"
},
and I check the dockers (in docker shell) /data/db folder, everything looks good:
ls -al
total 716
drwxr-xr-x 4 mongodb mongodb 4096 Mar 25 00:38 .
drwxr-xr-x 1 root root 4096 Mar 25 00:28 ..
-rw------- 1 mongodb mongodb 50 Mar 25 00:28 WiredTiger
-rw------- 1 mongodb mongodb 21 Mar 25 00:28 WiredTiger.lock
-rw------- 1 mongodb mongodb 1472 Mar 25 00:38 WiredTiger.turtle
-rw------- 1 mongodb mongodb 94208 Mar 25 00:38 WiredTiger.wt
-rw------- 1 mongodb mongodb 4096 Mar 25 00:28 WiredTigerHS.wt
-rw------- 1 mongodb mongodb 36864 Mar 25 00:34 _mdb_catalog.wt
-rw------- 1 mongodb mongodb 20480 Mar 25 00:29 collection-0--6476415430291015248.wt
-rw------- 1 mongodb mongodb 65536 Mar 25 00:34 collection-11--6476415430291015248.wt
-rw------- 1 mongodb mongodb 20480 Mar 25 00:29 collection-2--6476415430291015248.wt
-rw------- 1 mongodb mongodb 4096 Mar 25 00:28 collection-4--6476415430291015248.wt
-rw------- 1 mongodb mongodb 20480 Mar 25 00:33 collection-7--6476415430291015248.wt
-rw------- 1 mongodb mongodb 225280 Mar 25 00:33 collection-9--6476415430291015248.wt
drwx------ 2 mongodb mongodb 4096 Mar 25 00:39 diagnostic.data
-rw------- 1 mongodb mongodb 20480 Mar 25 00:29 index-1--6476415430291015248.wt
-rw------- 1 mongodb mongodb 73728 Mar 25 00:33 index-10--6476415430291015248.wt
-rw------- 1 mongodb mongodb 20480 Mar 25 00:34 index-12--6476415430291015248.wt
-rw------- 1 mongodb mongodb 20480 Mar 25 00:29 index-3--6476415430291015248.wt
-rw------- 1 mongodb mongodb 4096 Mar 25 00:28 index-5--6476415430291015248.wt
-rw------- 1 mongodb mongodb 4096 Mar 25 00:28 index-6--6476415430291015248.wt
-rw------- 1 mongodb mongodb 20480 Mar 25 00:33 index-8--6476415430291015248.wt
drwx------ 2 mongodb mongodb 4096 Mar 25 00:28 journal
-rw-r--r-- 1 root root 0 Mar 25 00:29 lueluelue
-rw------- 1 mongodb mongodb 2 Mar 25 00:28 mongod.lock
-rw------- 1 mongodb mongodb 36864 Mar 25 00:35 sizeStorer.wt
-rw------- 1 mongodb mongodb 114 Mar 25 00:28 storage.bson
However, here comes the problem: I found there's nothing in my "host machine"'s /data/docker/mongo_volume:
ubuntu#VM-0-9-ubuntu:/data/docker/mongo_volume$ ll
total 8
drwxr-xr-x 2 root root 4096 Mar 20 13:46 ./
drwxr-xr-x 3 root root 4096 Mar 20 13:46 ../
So anyone could give me a clue? thanks a lot!

Answer 1

your docker command is incorrect, you should place -v <host_folder>:<container_folder>, e.g.
sudo docker run -it -v /data/docker/mongo_volume:/data/db -d mongo