No valid host was found when setting up openstack to create an instance There are not enough hosts available. code:500

My virtual machine environment is centos7.2_1511.4g4 nucleus CPU

 

Many people say on the Internet that memory resources are insufficient , Checked the log of the computing node , Leng didn't see why ！

later fq After looking at the troubleshooting of other countries , It may be that the configuration file of the calculation is not configured properly , Finally, after modification, it is found that instances can be created ！

 Edit in all calculation nodes  /etc/nova/nova.conf  And modify it according to your application requirements .

cpu_allocation_ratio = 2.0 （ Twice the physical kernel can be used for total instances ） ram_allocation_ratio = 2.0 （ Twice the total memory can be used for total instances 

 Restart in all compute nodes  nova  and  nova-scheduler

systemctl restart openstack-nova-*

systemctl restart openstack-nova-scheduler.service