提示磁盘空间不足，这个要怎么解决，linux系统玩的少，不是很熟悉，错误如下示：

root@server02:/home/server02/kubernetes-starter# kubectl config set-cluster kubernetes  --server=http://192.168.2.102:8080
error: mkdir /root/.kube: no space left on device

磁盘使用情况

root@server02:/home/server02/kubernetes-starter# df -hl
Filesystem                         Size  Used Avail Use% Mounted on
udev                               967M     0  967M   0% /dev
tmpfs                              200M   24M  176M  12% /run
/dev/mapper/ubuntu--vg-ubuntu--lv  3.9G  3.9G     0 100% /
tmpfs                              997M     0  997M   0% /dev/shm
tmpfs                              5.0M     0  5.0M   0% /run/lock
tmpfs                              997M     0  997M   0% /sys/fs/cgroup
/dev/loop0                          87M   87M     0 100% /snap/core/4917
/dev/sda2                          976M  143M  767M  16% /boot
tmpfs                              200M     0  200M   0% /run/user/1000
/dev/loop1                          91M   91M     0 100% /snap/core/6405
overlay                            3.9G  3.9G     0 100% /var/lib/docker/overlay2/7b460d205fb047d81904ab009b91f8d156dc0c2305f3433cec614ebed4ad8e24/merged
shm                                 64M     0   64M   0% /var/lib/docker/containers/e8e96841c0550f2dafb46b857709f3647eb9f3474408c2d3551c643c1f928eb8/mounts/shm