No Valid Host From Host Aggregates Resulted in Instance Spawning Failure

Problem

• Cold Migration for the instance failed as it could not find any valid host for the instance to be deployed on.

• It queried the hosts available within host aggregates, however, since the flavor used for the instance did not match with any of the host aggregate metadata, migration failed.

None

# less nova-scheduler.log | grep [UUID]
INFO nova.filters [req-XYZ [UUID] [PROJECTUUID] - - -] Filtering removed all hosts for the request with instance ID '[UUID]'. Filter results: ['RetryFilter: (start: 8, end: 8)', 'AggregateMultiTenancyIsolation: (start: 8, end: 6)', 'AvailabilityZoneFilter: (start: 6, end: 6)', 'ServerGroupAffinityFilter: (start: 6, end: 6)', 'ServerGroupAntiAffinityFilter: (start: 6, end: 6)', 'AggregateInstanceExtraSpecsFilter: (start: 6, end: 0)']

None

# openstack server show [UUID] --fit-width
+-------------------------------------+------------------------------------------------------
|Field                              | Value                                                
+-------------------------------------+------------------------------------------------------
| OS-DCF:diskConfig                  | MANUAL                                                
| OS-EXT-AZ:availability_zone        | nova                                                  
| OS-EXT-PF9-SRV-RES-INFO:res_info    | {u'cfg_disk_gb': 150.0, u'vcpus': 4, u'cfg_memory_mb': 65536, u'cpu_mhz': 1000}                    |
| OS-EXT-SRV-ATTR:host                | [HOST]                  
| OS-EXT-SRV-ATTR:hypervisor_hostname | [HOSTNAME]                                  
| OS-EXT-SRV-ATTR:instance_name      | [INSTANCE_NAME]                 
| OS-EXT-STS:fault                    | {u'message': u'No valid host was found. <br>6 hosts failed with error: Can not find a host aggregate | matching instance extra spec requirement', u'code': 500, u'details': u'  File
| OS-EXT-STS:power_state              | Shutdown            
| OS-EXT-STS:task_state              | None                                                  
| OS-EXT-STS:vm_state                | stopped

Environment

• Platform9 Managed OpenStack - All Versions

Cause

Host aggregate to match the instance flavor specifications is not present.

None

# openstack flavor show SampleFlavor
+----------------------------+-----------------------+
| Field                      | Value                 |
+----------------------------+-----------------------+
| OS-FLV-DISABLED:disabled   | False                 |
| OS-FLV-EXT-DATA:ephemeral  | 0                     |
| access_project_ids         | None                  |
| disk                       | 80                    |
| id                         | 6                     |
| name                       | SampleFlavor          |
| os-flavor-access:is_public | True                  |
| properties                 | host='AggregateMatch' |
| ram                        | 8192                  |
| rxtx_factor                | 1.0                   |
| swap                       |                       |
| vcpus                      | 4                     |
+----------------------------+-----------------------+

None

# openstack aggregate list | grep sampleagg

Resolution

1. Create a host aggregate matching the Instance flavor specifications.

None

$ openstack aggregate create sampleagg 
$ openstack aggregate set --property host='AggregateMatch'
$ openstack aggregate add host 1 [HOST ID]

1. If the flavor properties is not set, it is mandatory to specify one or more key-value pairs that match the key-value pairs on the host aggregates with the scope aggregate_instance_extra_specs. For our case, it is the aggregate_instance_extra_specs: host='AggregateMatch' key-value pair.

2. Set the key-value pair using the following command.

None

$ openstack flavor set SampleFlavor --property host='AggregateMatch'

Additional Information

OpenStack Host Aggregate Document