The following warning is seen in the cinder-scheduler.log when volume type and extra specs are defined and the volume is in an error state. WARNING cinder.scheduler.manager [req-b6ef1628-fdc5-49e9-a40a-79d5fcedcfef c0c1ccd20639448c9deea5fe4c112a42 c8b023257513436f 8b303269988b2e7b|req-b6ef1628-fdc5-49e9-a40a-79d5fcedcfef c0c1ccd20639448c9deea5fe4c112a42 c8b023257513436f 8b303269988b2e7b] Failed to schedule_create_volume: No valid host was found.

Enable the option scheduler_driver=cinder.scheduler.simple.SimpleScheduler in the /etc/cinder/cinder.conf file and restart the cinder-scheduler service. The scheduler_driver defaults to cinder.scheduler.filter_scheduler.FilterScheduler.