Prevent bind mount from being managed by Proxmox?

[Bubbagump210]

I have an LXC container where I want to decouple the rootfs and a bind mount. I want to be able to backup, restore, and snapshot the rootfs completely separate from the bind mount. The bind mount I will then manage separately. The reasons being

* The bind mount is huge. Backups via PBS take forever as LXC doesn't have a dirty bitmap concept. Therefore I want to backup the bind mount via other means - ZFS replication.
* I want the rootfs to be able to be snapshotted and rolled back with out messing with bind mount so as to not mix the rootfs and bind mount ZFS snapshot dependencies.

Is it possible to have Proxmox mount the bind mount into the container but do none of the other management tasks with it?

 

[leesteken]

In my experience, if the container mount point is not on a Storage managed by Proxmox, it is not managed by Proxmox. I just use a directory on the Proxmox host as a container mount point in the configuration file (/etc/pve/lxc/100.conf) like this: mp0: /zfs_mount_point_on_host,mp=/directory_in_container,size=0T. I have not tested this with with snapshots and such but back-ups only back-up the riootfs.

 

[Bubbagump210]

That is what I am using currently and it does snapshot the bind mount unfortunately. Also, when I restore the rootfs it appears to clobber the exiting bind mount with a new one based on the definition in the lxc.conf. Avoiding backup is easy as that is a check box in the GUI or by omitting backup=1 in the mp line. Its the snapshot and clobbering on restore part I can't find an answer on.

 

[leesteken]

For my containers that use a mount point to a directory on the host (I think it is called a bind mount point in the Wiki), I cannot make snapshots. It tells me "The current guest configuration does not support taking new snapshots" in the Snapshot tab of the container. At least it prevents me from clobbering the mount point.
I guess you want to use snapshot and a bind mount point? Maybe add something like lxc.mount.entry: /host_path local_path none bind 0 0 to the configuration file? This works for the /dev/dvb/ for TV-tuners for example (with also a lxc.cgroup2.devices.allow and lxc.idmap).

EDIT: It seems to work. Just changed a mp0: /xyz,mp=/abc to lxc.mount.entry: /xyz abc none bind 0 0 and it mounted fine and allows snapshots.

 

[Bubbagump210]

That's the ticket, thank you!