centos 7 Failed to start Docker Application Container Engine. code example

Example: Failed to start Docker Application Container Engine

#Failed to start Docker Application Container Engine
sudo dockerd --debug # this command will show error
# if error is==> Error starting daemon: error while opening volume store metadata database: timeout
ps axf | grep docker | grep -v grep | awk '{print "kill -9 " $1}' | sudo sh
# Run above command it will fix the error
sudo systemctl start docker # it will start the docker
sudo systemctl status docker  # to check the satus of docker