1、当新增Node节点报磁盘空间不足error信息时候
（1）查看kubelet 应用根目录
[root@k8s-master home]# kubelet --help | grep root
如下图，1为docker应用的根目录，2为kubelet的根目录
（2）用 df -h 查看node节点磁盘空间大小，和du -h 命令查看var/lib/kubelet和var/lib/docker目录空间大小
[root@k8s-master ~]# df -h
Filesystem Size Used Avail Use% Mounted on
devtmpfs 1.4G 0 1.4G 0% /dev
tmpfs 1.4G 0 1.4G 0% /dev/shm
tmpfs 1.4G 11M 1.4G 1% /run
tmpfs 1.4G 0 1.4G 0% /sys/fs/cgroup
/dev/mapper/centos-root 50G 11G 40G 22% /
/dev/sr0 4.5G 4.5G 0 100% /media/cdrom
/dev/sda1 197M 163M 35M 83% /boot
tmpfs 283M 12K 283M 1% /run/user/42
[root@k8s-master ~]# du -h /var/lib/kubelet/
16K /var/lib/kubelet/pki
4.0K /var/lib/kubelet/device-plugins
0 /var/lib/kubelet/plugin-containers
0 /var/lib/kubelet/pod-resources
0 /var/lib/kubelet/pods/cab0b21434ee3210fc726e9c1ac70469/volumes
0 /var/lib/kubelet/pods/cab0b21434ee3210fc726e9c1ac70469/plugins
0 /var/lib/kubelet/pods/cab0b21434ee3210fc726e9c1ac70469/containers/etcd
0 /var/lib/kubelet/pods/cab0b21434ee3210fc726e9c1ac70469/containers
4.0K /var/lib/kubelet/pods/cab0b21434ee3210fc726e9c1ac70469
