remove /var/lib/kubelet/pods//volumes/kubernetes.io~downward-api/podinfo: device or resource busy

• 全部解挂载

# umount $(df -HT | grep '/var/lib/kubelet/pods' | awk '{print $7}')

• 一个个解挂载

# umount /var/lib/kubelet/pods/fb503576-95e0-11e6-bc6f-a0369f90f4d0/volumes/kubernetes.io~downward-api/podinfo