I try to install Kuberneties cluster on SLES. But When I do Kubeadm init using below command it gives given error.

Kubeadm init

kubeadm init  --pod-network-cidr=10.244.0.0/16 --kubernetes-version=1.15.3

Error

error execution phase preflight: [preflight] Some fatal errors occurred:
        [ERROR SystemVerification]: unsupported graph driver: btrfs
    [preflight] If you know what you are doing, you can make a check non-fatal with `--ignore-preflight-errors=...`

In SLES default file system is btrfs. So as per the official docker documentation Get Docker EE for SLES I add below in /etc/docker/daemon.json

{
  "storage-driver": "btrfs"
}

So what would be wrong? Need your kind assistance.

*********************************EDITED*************************************

Docker Status

systemctl status docker
● docker.service - Docker Application Container Engine
   Loaded: loaded (/usr/lib/systemd/system/docker.service; enabled; vendor preset: disabled)
  Drop-In: /usr/lib/systemd/system/docker.service.d
           └─flannel.conf
   Active: active (running) since Thu 2019-08-22 17:21:59 CST; 1h 21min ago
     Docs: https://docs.docker.com
 Main PID: 3188 (dockerd)
    Tasks: 24
   Memory: 52.9M
      CPU: 1.723s
   CGroup: /system.slice/docker.service
           └─3188 /usr/bin/dockerd --insecure-registry 192.***.***.***:***

Docker info

Containers: 2
 Running: 0
 Paused: 0
 Stopped: 2
Images: 1
Server Version: 18.09.4
Storage Driver: btrfs
 Build Version: Btrfs v4.9.1
 Library Version: 102
Logging Driver: json-file
Cgroup Driver: cgroupfs

Docker-ee version.

Client:
 Version:           18.09.4
 API version:       1.39
 Go version:        go1.10.6
 Git commit:        c3516c4
 Built:             Wed Mar 27 18:11:35 2019
 OS/Arch:           linux/amd64
 Experimental:      false

Server: Docker Engine - Enterprise
 Engine:
  Version:          18.09.4
  API version:      1.39 (minimum version 1.12)
  Go version:       go1.10.8
  Git commit:       c3516c4
  Built:            Wed Mar 27 18:05:47 2019
  OS/Arch:          linux/amd64
  Experimental:     false

df -Th

/dev/mapper/data_vg-var            btrfs      **G  407M   **G   1% /var
/dev/mapper/data_vg-var_lib        btrfs      **G  232M   **G   1% /var/lib
/dev/mapper/data_vg-var_lib_docker btrfs      **G   17M   **G   1% /var/lib/docker

sudo cat /proc/filesystems | grep btrfs

# sudo cat /proc/filesystems | grep btrfs
    btrfs

Edited /etc/docker/daemon.json as below

{
  "storage-driver": "btrfs"
}

Thank You