Thanks! That worked.
The full procedure was (where my storage pool is named lxd-partition and it’s located at /srv/lxd):
sudo mkdir /var/snap/lxd/common/lxd/storage-pools/lxd-partition
sudo nsenter --mount=/run/snapd/ns/lxd.mnt -- mount -o bind /var/lib/snapd/hostfs/srv/lxd /var/snap/lxd/common/lxd/storage-pools/lxd-partition
# list containers to import
sudo ls /srv/lxd/containers/
# for each container
sudo lxd import containername
As a suggestion, could you add this as a working example to the documentation at https://lxd.readthedocs.io/en/latest/backup/? I can see it’s partly documented, but there are important parts missing like using nsenter for Snap-installed LXD. And TBH it’s very non-intuitive without an example 