No valid host was found

asked 2014-09-25 06:31:26 -0600

MK gravatar image

updated 2014-09-25 08:23:45 -0600

larsks gravatar image

When I try to launch a instance i got below error.

Could any one help me on this


   No valid host was found.  Code
   500 Details
   File "/opt/stack/nova/nova/conductor/",
line 614, in build_instances
request_spec, filter_properties) File
line 49, in select_destinations
context, request_spec,
filter_properties) File
line 35, in __run_method return
getattr(self.instance, __name)(*args,
**kwargs) File "/opt/stack/nova/nova/scheduler/client/",
line 34, in select_destinations
context, request_spec,
filter_properties) File
line 107, in select_destinations
line 152, in call retry=self.retry)
line 90, in _send timeout=timeout,
retry=retry) File
line 408, in send retry=retry) File
line 399, in _send raise result


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"no valid host was found" can mean that (a) your compute nodes are not properly registered with your controller, or (b) that you are trying to start an instances that requirements more resources (e.g., memory, cpu, disk) than are available in your environment...

larsks gravatar imagelarsks ( 2014-09-25 08:25:00 -0600 )edit

What is the output of nova service-list on your system (you must run this command with admin credentials)?

larsks gravatar imagelarsks ( 2014-09-25 08:25:36 -0600 )edit

I've seen such message, when the provisioned instance requires too many resources, that obviously not always available on any of compute nodes.

fgorbat gravatar imagefgorbat ( 2014-09-25 14:16:08 -0600 )edit

when i run nova service-list it lists below nova-conductor, nova-cert,nova-scheduler, nova-consoleauth, nova-compute with status enabled

I am unable to put all data here as comment.

MK gravatar imageMK ( 2014-09-25 23:37:42 -0600 )edit

I have enough resources to launch a instance. I dont think problem with resources

MK gravatar imageMK ( 2014-09-25 23:39:27 -0600 )edit

1 answer

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answered 2015-09-11 07:55:13 -0600

Radhakrishnan Rk gravatar image

hi, "no valid host was found" is the common error while launching an instance in our openstack cloud..It may occurs due to multiples reasons such as lack of resources in your host(compute node(s)) which provides disk space and memory for your disk flavor to launch an instance..It may occurs due to the nova api is unable to communicate with nova compute node once it is scheduled to a specific host..

By the way,your error message conveys that your instance is scheduled in a host where there is no more resources available on it again communicates with the scheduler to pick an appropriate attempted the same thing until timeout..pls make sure whether you have resource to hold your instance as well as check whether all nova services are running in your controller node..if u deployed a multiple node setup,pls check the status of nova-compute..if it is not running..restart it

thanks, krishnaa

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Asked: 2014-09-25 06:31:26 -0600

Seen: 2,940 times

Last updated: Sep 11 '15