Validate which lxc mount points will be wiped during restore?

[EricD]

I have an LXC container with the following config running on pve-manager/7.4-15/a5d2a31e (running kernel: 5.15.102-1-pve)

arch: amd64 cores: 16 hostname: backups memory: 8192 mp0: /mnt/shared/backups,mp=/shared/backups mp7: /mnt/shared/library,mp=/shared/library net0: bridge=vmbr0,hwaddr=DA:01:F2:83:E0:02,name=eth0,ip=dhcp,ip6=dhcp,firewall=1 onboot: 1 ostype: ubuntu rootfs: local-zfs:subvol-107-disk-0,mountoptions=noatime,size=32G swap: 0 unprivileged: 1 lxc.idmap: u 0 100000 5000 lxc.idmap: g 0 100000 5000 lxc.idmap: u 5000 5000 100 lxc.idmap: g 5000 5000 100 lxc.idmap: u 5100 105100 60435 lxc.idmap: g 5100 105100 60435

I need to restore from backups but the big scary "going to wipe your mount points" makes me pause. mp0 and mp7 are bind mounts from the underlying OS and used by a bunch of things. They are not part of the backup and I really don't want to deal with them getting wiped and having to restore them.

 

[Dunuin]

For reference:

For containers, the situation is different, because the backup is done as a single filesystem, so if a mount point is excluded you will lose it upon restore. There is a warning for this.

 

[EricD]

What does "you will lose it upon restore" mean? Does it mean the restore wipes `/shared/backups` or the restored container will be missing the mount point?

 

[Dunuin]

As far as I understand it will wipe it. See:

CT 103 - Restore. This will permanently erase current CT data.
Mount point volumes are also erased.

And my mount point mp0 has not data no more ...

 

[fiona]

Hi,
mount point volumes are erased upon restore. But bind mounts are not erased.

 

[EricD]

Ok, so since mp0 and mp7 are bind mounts to directories on the host they will *not* be erased during a restore of this lxc? I'd like to verify I have all the terminology correct so I don't end up having to restore several TB from offsite

 

[fiona]

Ok, so since mp0 and mp7 are bind mounts to directories on the host they will *not* be erased during a restore of this lxc? I'd like to verify I have all the terminology correct so I don't end up having to restore several TB from offsite

Yes, they are bind mounts and those are not touched during restore. Of course it's better to ask in such cases. You can also try it with a dummy container if you'd like to make sure.

 

[EricD]

Just to circle back, I clicked through the scary warning and restored the LXC without wiping my bind mounts. Thank you all for your patience!