Safely sharing host directory amongst multiple LXC containers

[johnha]

A quick validation question for the gurus here:

Is it possible to bind mount a host directory to multiple LXC containers and not run into disk write conflicts?

Let's say there is a folder [or entire drive] on the host at /mnt/ssd/myfolder. And I have multiple unprivileged LXC containers, say 101, 102, 103, etc. for which I have the following in their configuration files: mp0: /mnt/ssd/myfolder/,mp=/mnt/sharedfolder. (Let's assume that I've mapped all the GID/UIDs properly so that these unprivileged containers have proper write access to the shared folder on the host.)

Is this safe?

I only ask because of some bad memories when I was first starting with PVE and I had some disk conflicts because I had multiple CTs writing to a host directory and causing data corruption.

Also, would it still be safe if I used this line in the config files[1] for 101, 102, 103, etc.:
lxc.mount.entry: /mnt/host/directory /mnt/guest/directory none bind 0 0

Is this also safe?

[1] Found at: https://forum.proxmox.com/threads/why-do-bind-mounts-prevent-snapshots.85495/

Many thanks in advance!

 

[Dunuin]

I only ask because of some bad memories when I was first starting with PVE and I had some disk conflicts because I had multiple CTs writing to a host directory and causing data corruption.

Are you sure you were bind-mounting folders into LXCs and not mounting block devices into VMs/LXCs?

 

[johnha]

Are you sure you were bind-mounting folders into LXCs and not mounting block devices into VMs/LXCs?

It must have been something like that.. I can't remember the exact configuration. But it was bad enough that I want a bit of reassurance that bind mounts can be rw mounted on multiple containers without conflict