javed alam <javedamar at gmail.com> wrote on 08/23/2014 02:39:38 PM: > From: javed alam <javedamar at gmail.com> > To: openstack <openstack at lists.openstack.org>, Masoom Alam > <masoom.alam at gmail.com> > Date: 08/23/2014 02:49 PM > Subject: [Openstack] Fwd: nova instance > > ... > "Error: Failed to launch instance "nova_testing": Please try again > later [Error: No valid host was found. ]. " > ... > i m even unable to find the log files. Hi Javed, the error "no valid host found" is thrown by the `nova-scheduler` service (see [1] for details). Depending on your testing environment you have to check different things: 1) An "All-In-One" DevStack[2] setup: * check your `local.conf` file in your devstack folder. There should be the following lines: DEST=/opt/stack LOGFILE=$DEST/logs/stack.sh.log VERBOSE=True SCREEN_LOGDIR=$DEST/logs/screen * The log of the scheduler is then available at: /opt/stack/logs/screen/screen-n-sch-log * The scheduler log should contain more information about the cause Afaik the changes will be applied when the services are restarted. You can either execute the DevStack scripts `unstack.sh` and `stack.sh` or use the screen tool (see [4]). 2) A dedicated controller node: The default folder for nova logs is `/var/log/nova`. The scheduler log should be there. Maybe you have to turn on debugging in the file `/etc/nova/nova.conf` in the line `debug=true` and `verbose=true`. More infos about working with logs can be found at [3]. Sources: [1] OpenStack configuration reference; Juno Release (draft); Section "Scheduling" http://docs.openstack.org/trunk/config-reference/content/section_compute-scheduler.html [2] DevStack; http://devstack.org/guides/single-machine.html [3] OpenStack Cloud Administrator Guide; Section "Manage Logs"; http://docs.openstack.org/admin-guide-cloud/content/section_manage-logs.html [4] IBM Developer Works; 2013-12-06; Restart services of devstack based openstack; https://www.ibm.com/developerworks/community/blogs/8160eff1-dedf-408e-9395-9dffeb68749f/entry/working_with_screens_to_restart_service_of_devstack_based_openstack?lang=en