用docker pull鏡像出現:failed to register layer: open /var/lib/docker/image/devicemapper/layerdb/tmp/write

用docker pull鏡像出現:failed to register layer: open /var/lib/docker/image/devicemapper/layerdb/tmp/write-set-450659526/diff: no space left on device

執行docker system prune -a這條代碼後，docker中未啓動的imges都會被清除

然後再pull，就成功了