Before 6.1, with the zfs LXC, the default storage driver would be the terrible vfs. So the only way was changing docker's config to use fuse-overlayfs. I installed 6.1, uninstalled fuse-overlayfs in the LXC, rebooted the pve node and then to my surprise in the LXC docker container I see this:
	
	
	
		Code:
	
	
		❯ uname -a
Linux docker2 6.1.10-1-pve #1 SMP PREEMPT_DYNAMIC PVE 6.1.10-1 (2023-02-07T00:00Z) x86_64 GNU/Linux
❯ docker info
Client:
 Context:    default
 Debug Mode: false
 Plugins:
  buildx: Docker Buildx (Docker Inc.)
    Version:  v0.10.2
    Path:     /usr/libexec/docker/cli-plugins/docker-buildx
  compose: Docker Compose (Docker Inc.)
    Version:  v2.6.1
    Path:     /root/.docker/cli-plugins/docker-compose
  scan: Docker Scan (Docker Inc.)
    Version:  v0.23.0
    Path:     /usr/libexec/docker/cli-plugins/docker-scan
Server:
 Containers: 29
  Running: 29
  Paused: 0
  Stopped: 0
 Images: 29
 Server Version: 23.0.1
 Storage Driver: overlay2
  Backing Filesystem: zfs
  Supports d_type: true
  Using metacopy: false
  Native Overlay Diff: true
  userxattr: false
 Logging Driver: json-file
 Cgroup Driver: systemd
 Cgroup Version: 2
 Plugins:
  Volume: local
  Network: bridge host ipvlan macvlan null overlay
  Log: awslogs fluentd gcplogs gelf journald json-file local logentries splunk syslog
 Swarm: inactive
 Runtimes: io.containerd.runc.v2 runc
 Default Runtime: runc
 Init Binary: docker-init
 containerd version: 2456e983eb9e37e47538f59ea18f2043c9a73640
 runc version: v1.1.4-0-g5fd4c4d
 init version: de40ad0
 Security Options:
  seccomp
   Profile: builtin
  cgroupns
 Kernel Version: 6.1.10-1-pve
 Operating System: Debian GNU/Linux 11 (bullseye)
 OSType: linux
 Architecture: x86_64
 CPUs: 4
 Total Memory: 8GiB
 Name: docker2
 ID: 1528994b-2a9b-49f8-8321-e1109edf5160
 Docker Root Dir: /var/lib/docker
 Debug Mode: false
 Username: alexdelprete
 Registry: https://index.docker.io/v1/
 Experimental: false
 Insecure Registries:
  127.0.0.0/8
 Live Restore Enabled: false