devstack screen 详解

n my previous blog i discussed how to install devstack based openstack. Now if I need to restart individual services of openstack, in a typical openstack install I would restart the service of each component, example nova-network service, horizon etc however in devstack  individual services are run as screens. First step would be to join the stack/screen as shown  in figure 1

 

Figure 1

After joining the screen  enter the following command ctrl + a + " , this will show all the devstack  screens as a  menu as shown in figure 2

 

Figure 2

 

Now lets say I modified the nova network config file and want to restart the service, the way I would do it is,press 9 and then cntrl C, this will stop(kill)   nova network service, now rerun the last command as shown in figure 3

 

Figure3

Once I run the command in figure 3, nova network service will start up and the changes to nova config file takes effect.  To detach from the screen and get back to the shell prompt enter the following keys on the keyboard cntrl a+d and will take me back to the shell prompt

Also at any given time to reinstall openstack, just have to run the following scripts present in the devstack directory

./unstack.sh

./stack.sh

 

Conclusion:

We are now able to modify openstack properties and restart individual  services. Also we know how to reinstall openstack if required.

Now in my next blog will move on to use the install to create a few virtual instances using the openstack horizon userinterface.