如果有container在運行的時候重啓 docker 服務， 可能會導致 container無法啓動， 錯誤信息類似於
Error response from daemon: Cannot start container zookeeper: Error getting container ddf1dd91bbf46dc648268327f8f7c6fffaf2f19cda5cf1d97fdc701016d4332c from driver devicemapper: Error mounting '/dev/mapper/docker-8:1-525372-ddf1dd91bbf46dc648268327f8f7c6fffaf2f19cda5cf1d97fdc701016d4332c'on'/var/lib/docker/devicemapper/mnt/ddf1dd91bbf46dc648268327f8f7c6fffaf2f19cda5cf1d97fdc701016d4332c': device or resource busy2015/01/2604:42:07 Error: failed tostart one or more containers
這是一個docker的 bug
解決方式是先找出沒有unmount的路徑
cat /proc/mounts | grep "mapper/docker" | awk '{print $2}'
然後依次unmount