NoValidHost: No valid host was found. There are not enough hosts available

aircraft picture aircraft · Aug 4, 2017 · Viewed 24.1k times · Source

When I create the instance in the dashboard, I get error:

No valid host was found. There are not enough hosts available.

In the /var/log/nova/nova-conductor.log file, there is the log:

2017-08-05 00:22:29.046 3834 WARNING nova.scheduler.utils [req-89c159c7-b40a-43eb-8f0d-9306eb73e83a 2a5fa182fb1b459980db09cd1572850e 0d5998f2f7ec4c4892a32e06bafb19df - - -] Failed to compute_task_build_instances: No valid host was found. There are not enough hosts available.
Traceback (most recent call last):

  File "/usr/lib/python2.7/site-packages/oslo_messaging/rpc/server.py", line 199, in inner
    return func(*args, **kwargs)

  File "/usr/lib/python2.7/site-packages/nova/scheduler/manager.py", line 104, in select_destinations
    dests = self.driver.select_destinations(ctxt, spec_obj)

  File "/usr/lib/python2.7/site-packages/nova/scheduler/filter_scheduler.py", line 74, in select_destinations
    raise exception.NoValidHost(reason=reason)

NoValidHost: No valid host was found. There are not enough hosts available.

2017-08-05 00:22:29.048 3834 WARNING nova.scheduler.utils [req-89c159c7-b40a-43eb-8f0d-9306eb73e83a 2a5fa182fb1b459980db09cd1572850e 0d5998f2f7ec4c4892a32e06bafb19df - - -] [instance: 2011e343-c8fc-4ed0-8148-b0d2b5ba37c3] Setting instance to ERROR state.
2017-08-05 00:22:30.785 3834 WARNING oslo_config.cfg [req-89c159c7-b40a-43eb-8f0d-9306eb73e83a 2a5fa182fb1b459980db09cd1572850e 0d5998f2f7ec4c4892a32e06bafb19df - - -] Option "auth_plugin" from group "neutron" is deprecated. Use option "auth_type" from group "neutron".

And I searched the SO, find a related post:Openstack-Devstack: Can't create instance, There are not enough hosts available

I checked the free_ram_mb in mysql:

MariaDB [nova]> select * from compute_nodes \G;
*************************** 1. row ***************************
           created_at: 2017-08-04 12:44:26
           updated_at: 2017-08-04 13:51:35
           deleted_at: NULL
                   id: 4
           service_id: NULL
                vcpus: 8
            memory_mb: 7808
             local_gb: 19
           vcpus_used: 0
       memory_mb_used: 512
        local_gb_used: 0
      hypervisor_type: QEMU
   hypervisor_version: 1005003
             cpu_info: {"vendor": "Intel", "model": "Broadwell", "arch": "x86_64", "features": ["smap", "avx", "clflush", "sep", "rtm", "vme", "invpcid", "msr", "fsgsbase", "xsave", "pge", "erms", "hle", "cmov", "tsc", "smep", "pcid", "pat", "lm", "abm", "adx", "3dnowprefetch", "nx", "fxsr", "syscall", "sse4.1", "pae", "sse4.2", "pclmuldq", "fma", "tsc-deadline", "mmx", "osxsave", "cx8", "mce", "de", "rdtscp", "ht", "pse", "lahf_lm", "rdseed", "popcnt", "mca", "pdpe1gb", "apic", "sse", "f16c", "ds", "invtsc", "pni", "aes", "avx2", "sse2", "ss", "hypervisor", "bmi1", "bmi2", "ssse3", "fpu", "cx16", "pse36", "mtrr", "movbe", "rdrand", "x2apic"], "topology": {"cores": 2, "cells": 1, "threads": 1, "sockets": 4}}
 disk_available_least: 18
          free_ram_mb: 7296
         free_disk_gb: 19
     current_workload: 0
          running_vms: 0
  hypervisor_hostname: ha-node1
              deleted: 0
              host_ip: 192.168.8.101
  supported_instances: [["i686", "qemu", "hvm"], ["x86_64", "qemu", "hvm"]]
            pci_stats: {"nova_object.version": "1.1", "nova_object.changes": ["objects"], "nova_object.name": "PciDevicePoolList", "nova_object.data": {"objects": []}, "nova_object.namespace": "nova"}
              metrics: []
      extra_resources: NULL
                stats: {}
        numa_topology: NULL
                 host: ha-node1
 ram_allocation_ratio: 3
 cpu_allocation_ratio: 16
                 uuid: 9113940b-7ec9-462d-af06-6988dbb6b6cf
disk_allocation_ratio: 1
*************************** 2. row ***************************
           created_at: 2017-08-04 12:44:34
           updated_at: 2017-08-04 13:50:47
           deleted_at: NULL
                   id: 6
           service_id: NULL
                vcpus: 8
            memory_mb: 7808
             local_gb: 19
           vcpus_used: 0
       memory_mb_used: 512
        local_gb_used: 0
      hypervisor_type: QEMU
   hypervisor_version: 1005003
             cpu_info: {"vendor": "Intel", "model": "Broadwell", "arch": "x86_64", "features": ["smap", "avx", "clflush", "sep", "rtm", "vme", "invpcid", "msr", "fsgsbase", "xsave", "pge", "erms", "hle", "cmov", "tsc", "smep", "pcid", "pat", "lm", "abm", "adx", "3dnowprefetch", "nx", "fxsr", "syscall", "sse4.1", "pae", "sse4.2", "pclmuldq", "fma", "tsc-deadline", "mmx", "osxsave", "cx8", "mce", "de", "rdtscp", "ht", "pse", "lahf_lm", "rdseed", "popcnt", "mca", "pdpe1gb", "apic", "sse", "f16c", "ds", "invtsc", "pni", "aes", "avx2", "sse2", "ss", "hypervisor", "bmi1", "bmi2", "ssse3", "fpu", "cx16", "pse36", "mtrr", "movbe", "rdrand", "x2apic"], "topology": {"cores": 2, "cells": 1, "threads": 1, "sockets": 4}}
 disk_available_least: 18
          free_ram_mb: 7296
         free_disk_gb: 19
     current_workload: 0
          running_vms: 0
  hypervisor_hostname: ha-node2
              deleted: 0
              host_ip: 192.168.8.102
  supported_instances: [["i686", "qemu", "hvm"], ["x86_64", "qemu", "hvm"]]
            pci_stats: {"nova_object.version": "1.1", "nova_object.changes": ["objects"], "nova_object.name": "PciDevicePoolList", "nova_object.data": {"objects": []}, "nova_object.namespace": "nova"}
              metrics: []
      extra_resources: NULL
                stats: {}
        numa_topology: NULL
                 host: ha-node2
 ram_allocation_ratio: 3
 cpu_allocation_ratio: 16
                 uuid: 32b574df-52ac-43dc-87f8-353350449076
disk_allocation_ratio: 1
2 rows in set (0.00 sec)

You see the free_ram_mb: 7296, I just want to create a 512mb VM, but failed.


EDIT-1

The nova services all are up:

[root@ha-node1 ~]# nova service-list
+----+------------------+----------+----------+---------+-------+----------------------------+-----------------+
| Id | Binary           | Host     | Zone     | Status  | State | Updated_at                 | Disabled Reason |
+----+------------------+----------+----------+---------+-------+----------------------------+-----------------+
| 2  | nova-consoleauth | ha-node3 | internal | enabled | up    | 2017-08-05T14:20:25.000000 | -               |
| 5  | nova-conductor   | ha-node3 | internal | enabled | up    | 2017-08-05T14:20:29.000000 | -               |
| 7  | nova-cert        | ha-node3 | internal | enabled | up    | 2017-08-05T14:20:23.000000 | -               |
| 15 | nova-scheduler   | ha-node3 | internal | enabled | up    | 2017-08-05T14:20:20.000000 | -               |
| 22 | nova-cert        | ha-node1 | internal | enabled | up    | 2017-08-05T14:20:26.000000 | -               |
| 29 | nova-conductor   | ha-node1 | internal | enabled | up    | 2017-08-05T14:20:22.000000 | -               |
| 32 | nova-consoleauth | ha-node1 | internal | enabled | up    | 2017-08-05T14:20:29.000000 | -               |
| 33 | nova-consoleauth | ha-node2 | internal | enabled | up    | 2017-08-05T14:20:29.000000 | -               |
| 36 | nova-scheduler   | ha-node1 | internal | enabled | up    | 2017-08-05T14:20:30.000000 | -               |
| 40 | nova-conductor   | ha-node2 | internal | enabled | up    | 2017-08-05T14:20:26.000000 | -               |
| 44 | nova-cert        | ha-node2 | internal | enabled | up    | 2017-08-05T14:20:27.000000 | -               |
| 46 | nova-scheduler   | ha-node2 | internal | enabled | up    | 2017-08-05T14:20:28.000000 | -               |
| 49 | nova-compute     | ha-node2 | nova     | enabled | up    | 2017-08-05T14:19:35.000000 | -               |
| 53 | nova-compute     | ha-node1 | nova     | enabled | up    | 2017-08-05T14:20:05.000000 | -               |
+----+------------------+----------+----------+---------+-------+----------------------------+-----------------+

The nova list:

[root@ha-node1 ~]# nova list 
+--------------------------------------+------+--------+------------+-------------+----------+
| ID                                   | Name | Status | Task State | Power State | Networks |
+--------------------------------------+------+--------+------------+-------------+----------+
| 20193e58-2c5b-44c6-a98f-a44e2001934f | vm1  | ERROR  | -          | NOSTATE     |          |

And the nova show instance:

[root@ha-node1 ~]# nova show 20193e58-2c5b-44c6-a98f-a44e2001934f
+--------------------------------------+------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+
| Property                             | Value                                                                                                                                                                                                      |
+--------------------------------------+------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+
| OS-DCF:diskConfig                    | AUTO                                                                                                                                                                                                       |
| OS-EXT-AZ:availability_zone          | nova                                                                                                                                                                                                       |
| OS-EXT-SRV-ATTR:host                 | -                                                                                                                                                                                                          |
| OS-EXT-SRV-ATTR:hostname             | vm1                                                                                                                                                                                                        |
| OS-EXT-SRV-ATTR:hypervisor_hostname  | -                                                                                                                                                                                                          |
| OS-EXT-SRV-ATTR:instance_name        | instance-00000003                                                                                                                                                                                          |
| OS-EXT-SRV-ATTR:kernel_id            |                                                                                                                                                                                                            |
| OS-EXT-SRV-ATTR:launch_index         | 0                                                                                                                                                                                                          |
| OS-EXT-SRV-ATTR:ramdisk_id           |                                                                                                                                                                                                            |
| OS-EXT-SRV-ATTR:reservation_id       | r-jct8kkcq                                                                                                                                                                                                 |
| OS-EXT-SRV-ATTR:root_device_name     | /dev/vda                                                                                                                                                                                                   |
| OS-EXT-SRV-ATTR:user_data            | -                                                                                                                                                                                                          |
| OS-EXT-STS:power_state               | 0                                                                                                                                                                                                          |
| OS-EXT-STS:task_state                | -                                                                                                                                                                                                          |
| OS-EXT-STS:vm_state                  | error                                                                                                                                                                                                      |
| OS-SRV-USG:launched_at               | -                                                                                                                                                                                                          |
| OS-SRV-USG:terminated_at             | -                                                                                                                                                                                                          |
| accessIPv4                           |                                                                                                                                                                                                            |
| accessIPv6                           |                                                                                                                                                                                                            |
| config_drive                         |                                                                                                                                                                                                            |
| created                              | 2017-08-05T14:17:54Z                                                                                                                                                                                       |
| description                          | vm1                                                                                                                                                                                                        |
| fault                                | {"message": "No valid host was found. There are not enough hosts available.", "code": 500, "details": "  File \"/usr/lib/python2.7/site-packages/nova/conductor/manager.py\", line 496, in build_instances |
|                                      |     context, request_spec, filter_properties)                                                                                                                                                              |
|                                      |   File \"/usr/lib/python2.7/site-packages/nova/conductor/manager.py\", line 567, in _schedule_instances                                                                                                    |
|                                      |     hosts = self.scheduler_client.select_destinations(context, spec_obj)                                                                                                                                   |
|                                      |   File \"/usr/lib/python2.7/site-packages/nova/scheduler/utils.py\", line 370, in wrapped                                                                                                                  |
|                                      |     return func(*args, **kwargs)                                                                                                                                                                           |
|                                      |   File \"/usr/lib/python2.7/site-packages/nova/scheduler/client/__init__.py\", line 51, in select_destinations                                                                                             |
|                                      |     return self.queryclient.select_destinations(context, spec_obj)                                                                                                                                         |
|                                      |   File \"/usr/lib/python2.7/site-packages/nova/scheduler/client/__init__.py\", line 37, in __run_method                                                                                                    |
|                                      |     return getattr(self.instance, __name)(*args, **kwargs)                                                                                                                                                 |
|                                      |   File \"/usr/lib/python2.7/site-packages/nova/scheduler/client/query.py\", line 32, in select_destinations                                                                                                |
|                                      |     return self.scheduler_rpcapi.select_destinations(context, spec_obj)                                                                                                                                    |
|                                      |   File \"/usr/lib/python2.7/site-packages/nova/scheduler/rpcapi.py\", line 126, in select_destinations                                                                                                     |
|                                      |     return cctxt.call(ctxt, 'select_destinations', **msg_args)                                                                                                                                             |
|                                      |   File \"/usr/lib/python2.7/site-packages/oslo_messaging/rpc/client.py\", line 169, in call                                                                                                                |
|                                      |     retry=self.retry)                                                                                                                                                                                      |
|                                      |   File \"/usr/lib/python2.7/site-packages/oslo_messaging/transport.py\", line 97, in _send                                                                                                                 |
|                                      |     timeout=timeout, retry=retry)                                                                                                                                                                          |
|                                      |   File \"/usr/lib/python2.7/site-packages/oslo_messaging/_drivers/amqpdriver.py\", line 464, in send                                                                                                       |
|                                      |     retry=retry)                                                                                                                                                                                           |
|                                      |   File \"/usr/lib/python2.7/site-packages/oslo_messaging/_drivers/amqpdriver.py\", line 455, in _send                                                                                                      |
|                                      |     raise result                                                                                                                                                                                           |
|                                      | ", "created": "2017-08-05T14:18:14Z"}                                                                                                                                                                      |
| flavor                               | m1.tiny (1)                                                                                                                                                                                                |
| hostId                               |                                                                                                                                                                                                            |
| host_status                          |                                                                                                                                                                                                            |
| id                                   | 20193e58-2c5b-44c6-a98f-a44e2001934f                                                                                                                                                                       |
| image                                | cirros-0.3.4-x86_64 (202778cd-6b32-4486-9444-c167089d9082)                                                                                                                                                 |
| key_name                             | -                                                                                                                                                                                                          |
| locked                               | False                                                                                                                                                                                                      |
| metadata                             | {}                                                                                                                                                                                                         |
| name                                 | vm1                                                                                                                                                                                                        |
| os-extended-volumes:volumes_attached | []                                                                                                                                                                                                         |
| status                               | ERROR                                                                                                                                                                                                      |
| tags                                 | []                                                                                                                                                                                                         |
| tenant_id                            | 0d5998f2f7ec4c4892a32e06bafb19df                                                                                                                                                                           |
| updated                              | 2017-08-05T14:18:16Z                                                                                                                                                                                       |
| user_id                              | 2a5fa182fb1b459980db09cd1572850e                                                                                                                                                                           |
+--------------------------------------+------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+

EDIT-2

The nova-compute.log in the /var/log/nova/ useful information:

......
2017-08-05 22:17:42.669 103174 INFO nova.compute.resource_tracker [req-60a062ce-4b3d-4cb7-863e-2f9bba0bc6ec - - - - -] Compute_service record updated for ha-node1:ha-node1
2017-08-05 22:18:03.357 103174 ERROR nova.compute.manager [req-7dded91f-7497-4d20-ba89-69f867a2a8fb 2a5fa182fb1b459980db09cd1572850e 0d5998f2f7ec4c4892a32e06bafb19df - - -] [instance: 20193e58-2c5b-44c6-a98f-a44e2001934f] Instance failed to spawn
2017-08-05 22:18:03.357 103174 ERROR nova.compute.manager [instance: 20193e58-2c5b-44c6-a98f-a44e2001934f] Traceback (most recent call last):
2017-08-05 22:18:03.357 103174 ERROR nova.compute.manager [instance: 20193e58-2c5b-44c6-a98f-a44e2001934f]   File "/usr/lib/python2.7/site-packages/nova/compute/manager.py", line 2078, in _build_resources
2017-08-05 22:18:03.357 103174 ERROR nova.compute.manager [instance: 20193e58-2c5b-44c6-a98f-a44e2001934f]     yield resources
2017-08-05 22:18:03.357 103174 ERROR nova.compute.manager [instance: 20193e58-2c5b-44c6-a98f-a44e2001934f]   File "/usr/lib/python2.7/site-packages/nova/compute/manager.py", line 1920, in _build_and_run_instance
2017-08-05 22:18:03.357 103174 ERROR nova.compute.manager [instance: 20193e58-2c5b-44c6-a98f-a44e2001934f]     block_device_info=block_device_info)
2017-08-05 22:18:03.357 103174 ERROR nova.compute.manager [instance: 20193e58-2c5b-44c6-a98f-a44e2001934f]   File "/usr/lib/python2.7/site-packages/nova/virt/libvirt/driver.py", line 2584, in spawn
2017-08-05 22:18:03.357 103174 ERROR nova.compute.manager [instance: 20193e58-2c5b-44c6-a98f-a44e2001934f]     admin_pass=admin_password)
2017-08-05 22:18:03.357 103174 ERROR nova.compute.manager [instance: 20193e58-2c5b-44c6-a98f-a44e2001934f]   File "/usr/lib/python2.7/site-packages/nova/virt/libvirt/driver.py", line 2959, in _create_image
2017-08-05 22:18:03.357 103174 ERROR nova.compute.manager [instance: 20193e58-2c5b-44c6-a98f-a44e2001934f]     fileutils.ensure_tree(libvirt_utils.get_instance_path(instance))
2017-08-05 22:18:03.357 103174 ERROR nova.compute.manager [instance: 20193e58-2c5b-44c6-a98f-a44e2001934f]   File "/usr/lib/python2.7/site-packages/oslo_utils/fileutils.py", line 40, in ensure_tree
2017-08-05 22:18:03.357 103174 ERROR nova.compute.manager [instance: 20193e58-2c5b-44c6-a98f-a44e2001934f]     os.makedirs(path, mode)
2017-08-05 22:18:03.357 103174 ERROR nova.compute.manager [instance: 20193e58-2c5b-44c6-a98f-a44e2001934f]   File "/usr/lib64/python2.7/os.py", line 157, in makedirs
2017-08-05 22:18:03.357 103174 ERROR nova.compute.manager [instance: 20193e58-2c5b-44c6-a98f-a44e2001934f]     mkdir(name, mode)
2017-08-05 22:18:03.357 103174 ERROR nova.compute.manager [instance: 20193e58-2c5b-44c6-a98f-a44e2001934f] OSError: [Errno 13] Permission denied: '/var/lib/nova/instances/20193e58-2c5b-44c6-a98f-a44e2001934f'
2017-08-05 22:18:03.357 103174 ERROR nova.compute.manager [instance: 20193e58-2c5b-44c6-a98f-a44e2001934f]
2017-08-05 22:18:11.563 103174 INFO nova.compute.manager [req-7dded91f-7497-4d20-ba89-69f867a2a8fb 2a5fa182fb1b459980db09cd1572850e 0d5998f2f7ec4c4892a32e06bafb19df - - -] [instance: 20193e58-2c5b-44c6-a98f-a44e2001934f] Terminating instance
....

Answer

Arun prasath picture Arun prasath · Aug 5, 2017

First you need to check the output of "nova service-list" or "openstack compute service list". It should show at least one 'nova-compute' service with state as "Up" and status as 'enabled'.

If the above is fine, then the compute nodes are communicating properly with the scheduler. If not, then you need to check the nova-scheduler logs.

The nova-scheduler has a series of filters like Memory filter, CPU filter, Aggregate filter which it is apply to filter hosts based on the flavor you selected. i.e If you select a flavor with 16GB RAM, then the scheduler will filter (Memory filter) compute hosts which has the available memory. After all the filtering is done the scheduler will try to launch instance on a filtered host, if it fails it will try on another host. Default number of tries is 3. All these can be seen in scheduler logs. That will give you a clear idea on what went wrong.

Also you need to check 'nova show ' output. If you can see the compute host present in "OS-EXT-SRV-ATTR:hypervisor_hostname" , then we can understand that the scheduler was successfully able to allocate a compute host and something went wrong with the compute host. In that case, you need to check the nova-compute logs of that hypervisor.