Cannot write to local NFS mount from either root or within CTs


New Member
Dec 24, 2023
hi everyone, i'm having a blast using proxmox!

I'm facing an issue with how i want to organize my lxc infrastructure. here a brief roundup of the setup:
  • single node (neuromancer) running both VMs and CTs
  • zfs pool ("vault") with a few datasets (both used for proxmox storage and user storage). the relevant dataset here is "/vault/arr", created specifically to be mounted as nfs share. dataset has sharenfs=on
  • "/vault/arr" dataset is mounted as nfs share on the host "/mnt/pve/nfs-arr" (i've done this in the webgui from the datacenter > storage tab). The forum post i followed is this.
The first issue is that, after creating the nfs share, i cannot write to it from the pve root user:

root@neuromancer:~# touch /mnt/pve/nfs-arr/test
touch: cannot touch '/mnt/pve/nfs-arr/test': Permission denied

this is the ownership situation of /mnt/pve/nfs-arr

root@neuromancer:~# ls -ld /mnt/pve/nfs-arr/
drwxr-xr-x 3 root root 3 Dec 24 11:22 /mnt/pve/nfs-arr/

this is the result if i try to chown from the pve root user:

root@neuromancer:~# chown -R 1005:1005 /mnt/pve/nfs-arr
chown: changing ownership of '/mnt/pve/nfs-arr/snippets': Operation not permitted
chown: changing ownership of '/mnt/pve/nfs-arr': Operation not permitted

i have another moutpoint for a different disk in the same /mnt/pve folder, and i can write to it fine when the disk is connected to the system.

Previously, i was bind-mounting the dataset "vault/arr" directly to the CTs as described here, and i chown'ed the dataset directly to 1005:1005. This dataset doesn't exist anymore but the setup worked. I was, however, worried about data corruption due to multiple CTs accessing the same dataset at the same time (both writes and reads), so i decided to switch to bind-mounting a local nfs share of the dataset, hoping that accessing the dataset though a network share fs would have prevented it.

Why is the first issue happening? i thought the host root user would have had total access to every folder of the host fs.


The Proxmox community has been around for many years and offers help and support for Proxmox VE, Proxmox Backup Server, and Proxmox Mail Gateway.
We think our community is one of the best thanks to people like you!

Get your subscription!

The Proxmox team works very hard to make sure you are running the best software and getting stable updates and security enhancements, as well as quick enterprise support. Tens of thousands of happy customers have a Proxmox subscription. Get yours easily in our online shop.

Buy now!