Can a PVE container access ZFS subvol of another container?


Jun 25, 2019
Can a PVE container access ZFS subvol of another container?

I am trying to setup TKL Syncthing on a r720xd server running Proxmox VE 5.4-11. I have the Syncthing CT installed and running. On the same PVE I also have a TKL File Server CT running.

On the r720xd, I have a ZFS pool created, which is currently only used for TKL File Server as a NAS. All shares in TKL File Server are working great - r/w accessible by clients on the LAN.

The ZFS pool is mounted to the PVE host as /r720xd1

/r720xd1 has two subdirectories for the only two containers running under PVE:

/r720xd1/subvol-104-disk-0 # For TKL Syncthing

/r720xd1/subvol-108-disk-0 # For TKL File Server

subvol-108 was created when I added a mountpoint of /srv/storage for the TKL File Server. This was done to utilize the ZFS file system as the storage for TKL File Server shares.

subvol-104 was created when I added a mountpoint /r720xd1/subvol-108-disk-0/syncthing . This was done in an attempt to directly access and utilize the /syncthing share in my TKL File Server directory.

I logged in to the Syncthing webGUI from a client on the LAN and changed Actions>Settings>Default Folder Path to: /r720xd1/subvol-108-disk-0/syncthing

When I try to create a new 'test' Folder to share via Synthing from the webGUI I receive:

Failed to create folder root directory mkdir /r720xd1/subvol-108-disk-0/syncthing/test: permission denied.

So I have to assume the default user 'syncthing' (or the entire 104 container) does not have permission to write to the /r720xd1/subvol-108-disk-0 - presumably because this is the subvol for a different container.

How can I grant user syncthing in this container (or container 104) r/w access to a subvol in container 108? OR: What would be the best-case practice to utilize the storage hosted by TKL File Server on subvol-108 for Syncthing running in container 104?
This seems way to complex for file sharing. Why not just use a second mountpoint (mp) and configure the container to be file server and sync station? Way easier, than trying to handle multi client locks for open files.


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