Why do bind mounts prevent snapshots?

[timdonovan]

mp0 are checked in the PVE logic, lxc.mount.entry are not.

Thanks - what does this actually mean though?

 

[LnxBil]

Thanks - what does this actually mean though?

In this context: PVE is "just" an additional layer around a LX(C) container, which adds new features. mp0 is PVE logic and therefore implies "not snapshottable", the setting lxc.mount.entry is a basic setting and will be ignored by PVE and only directly interpreted by the LXC logic.

 

[Sarke]

To snapshot,
1. Shutdown machine
2. Backup /etc/pve/nodes/eno/qemu-server/ VMID .conf
3. Detatch the offending drives
4. Snapshot
5. Add detached drive entries into conf
6. Boot

I want to add that when you do this, Proxmox will "forget" about any snapshots you've taken and no longer list them on the Snapshots tab. Removing the drive won't bring them back either, but they are still there as ZFS snapshots (or whatever format you have). So going with `lxc.mount.entry` seems to be the better option.

 

[ArionWolf]

This workaround does not seem to work for me. I get an LXC attach error if I leave out the slash just before the second directory (in container), if I include the forward slash the container starts but does not contain the directory/bind mount.

I am trying to mount two cephfses and one tmpfs on two separate unprivileged containers. So I guess it's not a regular directory/mount and requires some more trickery to get going.

I had problem with lxc.mount.entry turned out that I need to use rbind instead of bind because the folder I was trying to mount had folders in it.

Found the solution thanks to this post https://forum.proxmox.com/threads/mount-propagation-in-lxc-containers.150747/post-681682

 

[usei]

mp has options 'replicate' and ‘shared‘. Can I use theses also with lxc.mount.entry?

 

[ArionWolf]

I dont think so but I dont have experience with replicate ablnd shared options. With lxc.mount.entry you will not even see the mount in the resources