[Solved] Docker unable to mount nfs

crc_error_79 · April 24, 2023, 1:43pm

Hello,

I am going mad with nfs (on truenas) and docker. I think it is a permission thing but I don’t know how to solve it.

This is the error message I get when composer starts with the right dataset (media_nas)

docker compose up -d
[+] Running 2/3
 ✔ Network docker_default     Created                                                                                                                                                0.0s 
 ✔ Volume "docker_media_nas"  Created                                                                                                                                                0.0s 
 ⠙ Container jellyfin         Creating                                                                                                                                               0.1s 
Error response from daemon: failed to copy file info for /var/lib/docker/volumes/docker_media_nas/_data: failed to chown /var/lib/docker/volumes/docker_media_nas/_data: lchown /var/lib/docker/volumes/docker_media_nas/_data: operation not permitted

this is my test docker-composer.yml

services:

  jellyfin:
    container_name: jellyfin
    image: jellyfin/jellyfin
    user: 1000:1000
    volumes:
      - /etc/localtime:/etc/localtime:ro
      - ./jellyfin/config:/config
      - ./jellyfin/cache:/cache
      - media_nas:/media                #  <== this not work
#      - registrazioni:/media           #  <== this work       
    ports:
      - 8096:8086
      - 8920:8920
      - 1900:1900
      - 7359:7359
    restart: unless-stopped
    runtime: nvidia
    deploy:
      resources:
        reservations:
          devices:
            - capabilities: [gpu]
    environment:
      - NVIDIA_VISIBLE_DEVICES=all
      - NVIDIA_DRIVER_CAPABILITIES=compute,video,utility
      - TZ=Europe/Rome


volumes:
  media_nas:
    driver: local
    driver_opts:
      type: nfs
      o: addr=192.168.207.10,nolock,soft,rw,vers=4
      device:  :/mnt/domotica_6/media

  registrazioni:
    driver: local
    driver_opts:
      type: nfs
      o: addr=192.168.207.10,nolock,soft,rw,vers=4
      device:  :/mnt/telecamere/frigate_registrazioni

If I swap the device path, from “media_nas” to “registrazioni” everything works

here the log

casa@domotica:~/docker$ docker volume rm docker_media_nas
docker_media_nas


root@domotica:/var/lib/docker/volumes# ls -l
total 32
brw------- 1 root root 254, 1 Apr 24 13:53 backingFsBlockDev
drwx-----x 3 root root   4096 Apr 24 15:32 docker_media_nas
drwx-----x 3 root root   4096 Apr 24 15:35 docker_registrazioni
-rw------- 1 root root  32768 Apr 24 15:35 metadata.db


root@domotica:/var/lib/docker/volumes# ls -l docker_media_nas
total 8
drwxr-xr-x 2 root root 4096 Apr 24 15:32 _data
-rw------- 1 root root  133 Apr 24 15:32 opts.json

root@domotica:/var/lib/docker/volumes# ls -l docker_registrazioni
total 13
drwxrwxr-x 10 3001 3001  12 Apr 24 14:56 _data
-rw-------  1 root root 149 Apr 24 15:35 opts.json

“docker_registrazioni” get the right user and group 3001:3001 set on Truenas for this share but “media_nas” not and remain with the root…

How can I solve?

LTS_Tom · April 24, 2023, 4:23pm

My solution is to use fstab to mount the NFS shares to the system and then specify the paths in docker-compose file

volumes:    
      - "/mnt/TrueNAS_NFS/Share:/usr/share/data"

crc_error_79 · April 24, 2023, 5:34pm

Thank you @LTS_Tom , later I will do some test with your solution

In meantime now I fixed the issue I had creating and user and a group (on the host machine) with the same number of the user I used to create the nfs share on truenas.

I am not a big expert on that, is your solution better?

Because using my fix I have to carbon copy the users (or at least groups) I have on truenas…

# create a group with same number of the nfs share
sudo groupadd -g 3001 gaia_media

#create a new user with same id and group of the nfs share
sudo useradd -u 3001 -g 3001 gaia_media

# se a password for the new user (i don t know if it is necessary)
sudo passwd gaia_media 

# add my local user (casa) to the gaia_media group, so I can mount the nfs on the host and rw because group on nfs share has write permissions
sudo usermod -aG gaia_media casa

then I modified the docker-compose.yml to run jellyfin as user with ID 1000 (casa): 3001 (gaia_media)

services:

  jellyfin:
    container_name: jellyfin
    image: jellyfin/jellyfin
    user: 1000:3001
    volumes:
      - /etc/localtime:/etc/localtime:ro
      - ./jellyfin/config:/config
      - ./jellyfin/cache:/cache
      - media:/media
    network_mode: host # <= I want to fix this to use the port instead
#    ports:
#      - 8096:8086
#      - 8920:8920
#      - 1900:1900
#      - 7359:7359
    restart: unless-stopped
    runtime: nvidia
    deploy:
      resources:
        reservations:
          devices:
            - capabilities: [gpu]
    environment:
      - NVIDIA_VISIBLE_DEVICES=all
      - NVIDIA_DRIVER_CAPABILITIES=compute,video,utility
      - TZ=Europe/Rome


volumes: 
  media:
    driver: local
    driver_opts:
      type: nfs
      o: nfsvers=4,addr=192.168.207.10,rw,nolock,soft
      device: :/mnt/domotica_6/media

  registrazioni:
    driver: local
    driver_opts:
      type: nfs
      o: nfsvers=4,addr=192.168.207.10,rw,nolock,soft
      device:  :/mnt/telecamere/frigate_registrazioni

and it works! And works also the nvidia encoding/decoding (another thing I had to try), I am happy an entire afternoon trashed but now works

xMAXIMUSx · April 24, 2023, 6:19pm

Welcome to the world of Information Technology (IT).

David · April 25, 2023, 12:39pm

This unfortunately is not the most optimal solution because docker will create a new directory locally when the nfs volume is not mounted (such as failing to mount on boot, network outage, etc). The problem is that the app will start on a blank slate and you would have to go in, shutdown the container, re-mount the nfs volume, and then start the container back up. If you define NFS via the docker-compose file, the container will just fail to start until the nfs target is available (which is what it should do).

Javi · April 27, 2026, 6:17pm

Hello,

I have had the same issue with that as well where I would just like to mount the nfs shares to the container. the way I got passed this issue is you must set the dataset ACL type to POSIX. (it will be under Advanced Options)

Then you will need to maproot user to root`, and the Maproot Group to wheel (it will be under Advanced Options in Edit NFS Share)

And then you can just mount it to the volume just like any other compose file.
volumes:

volumes:
  linuxisos-movies:
    driver: local
    driver_opts:
      type: nfs
      o: addr=10.30.30.101,rw,nfsvers=4
      device: ":/mnt/DataDumpster/Linux_Isos/movies"

hope this helps someone out.