Resize LXD container

Well I’ve already increased that LVM volume and using lvreduce is risky. How do I tell LXD exactly to do that since it’s not working… What I’ve tried so far:

lxc config device override vs1 root size=250G
lxc restart vs1

Inside the container I’m still seeing the 10G disk space.

And here’s the container’s info:

lxc config show vs1
architecture: x86_64
config:
  image.architecture: amd64
  image.description: ubuntu 20.04 LTS amd64 (release) (20200921.1)
  image.label: release
  image.os: ubuntu
  image.release: focal
  image.serial: "20200921.1"
  image.type: squashfs
  image.version: "20.04"
  volatile.base_image: 4746a4889a31e449e6c5e2764eb733a60e85131be3165c91d5f5a8346f0ba43c
  volatile.eth0.host_name: vethe5a2ef7a
  volatile.eth0.hwaddr: 00:16:3e:1c:dc:f3
  volatile.idmap.base: "0"
  volatile.idmap.current: '[{"Isuid":true,"Isgid":false,"Hostid":1000000,"Nsid":0,"Maprange":1000000000},{"Isuid":false,"Isgid":true,"Hostid":1000000,"Nsid":0,"Maprange":1000000000}]'
  volatile.idmap.next: '[{"Isuid":true,"Isgid":false,"Hostid":1000000,"Nsid":0,"Maprange":1000000000},{"Isuid":false,"Isgid":true,"Hostid":1000000,"Nsid":0,"Maprange":1000000000}]'
  volatile.last_state.idmap: '[{"Isuid":true,"Isgid":false,"Hostid":1000000,"Nsid":0,"Maprange":1000000000},{"Isuid":false,"Isgid":true,"Hostid":1000000,"Nsid":0,"Maprange":1000000000}]'
  volatile.last_state.power: RUNNING
devices:
  root:
    path: /
    pool: default
    size: 250G
    type: disk
ephemeral: false
profiles:
- default
stateful: false
description: ""

Alternatively, would it be possible to create a new container, with a predefined disk size, create a full backup for the running container and then somehow restore the backup to the new container while keeping the disk size?