I am trying to launch a cirros instance and it's giving me the below error
Error: Failed to perform requested operation on instance "green", the instance has an error status: Please try again later [Error: No valid host was found. There are not enough hosts available.].
[Error: No valid host was found. There are not enough hosts available.]
This error means your instance does not find a host on which it can run. This is possibly due to the following two reasons --
1) If the compute node does have enough availabe resources like memory or vcpu's.
2) Nova compute service is not running or malfunctioning. This problems also arises when you shutdown your system. Use the command on compute node it worked for me
$ sudo service nova-compute restart.
and if the compute node does have enough vcpu/memory , please check whether it cannot connect to AMQP which is typically built on the controller node
Asked: 2017-06-19 08:37:46 -0500
Seen: 617 times
Last updated: Jun 20 '17
It means that none of the compute nodes in your cloud is able to run the Cirros VM, e.g. they do n't have enough capacity, or not the appropriate CPU, or many other reasons. Find more information in the Nova scheduler log file on the controller node, and the Nova compute logs on compute nodes.
Also check /var/log/libvirt/libxl/libxl-driver.log, this can help if nova-compute.log is not clear enough. This way I found out that xen VMs need a special kernel, or that my hypervisor was out of memory.