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

Question

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 1

Debugging
Enable debug mode to get detailed logs.
Set debug = True in these files:
/etc/nova/nova.conf
/etc/nova/cinder.conf
/etc/glance/glance-registry.conf
Restart the reconfigured services
Try to create instance again and check logs.
Take a look at the nova-scheduler.log file and try to find line like this:
.. INFO nova.filters [req-..] Filter DiskFilter returned 0 hosts
Above this line should be DEBUG logs with Filters detailed information, for example:
.. DEBUG nova.filters [req-..] Filter RetryFilter returned 1 host(s) get_filtered_objects /usr/lib/python2.7/site-packages/nova/filters.py:104
.. DEBUG nova.filters [req-..] Filter AvailabilityZoneFilter returned 1 host(s) get_filtered_objects /usr/lib/python2.7/site-packages/nova/filters.py:104
.. DEBUG nova.filters [req-..] Filter RamFilter returned 1 host(s) get_filtered_objects /usr/lib/python2.7/site-packages/nova/filters.py:104
.. DEBUG nova.filters [req-..] (...) ram: 37107MB disk: 11264MB io_ops: 0 instances: 4 does not have 17408 MB usable disk, it only has 11264.0 MB usable disk. host_passes /usr/lib/python2.7/site-packages/nova/scheduler/filters/disk_filter.py:70
Overcommitting
OpenStack allows you to overcommit CPU and RAM on compute nodes. This allows you to increase the number of instances running on your cloud at the cost of reducing the performance of the instances. The Compute service uses the following ratios by default:
CPU allocation ratio: 16:1
RAM allocation ratio: 1.5:1
Please read documentation to get more information.
You can change allocation ratio using nova.conf:
cpu_allocation_ratio
ram_allocation_ratio
disk_allocation_ratio

Answer 2

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.

Answer 3

Finally I found I mount the /var/lib/nova/ to nfs directory /mnt/sdb/var/lib/nova/, but the /mnt/sdb/var/lib/nova/ permission is root:root, so I changed to the nova:nova(same to the /var/lib/nova/).
command :
chown -R nova:nova nova

Answer 4

edit /etc/nova/nova.conf in all the compute node and modify as per your application requirement .
cpu_allocation_ratio = 2.0
( double of physical core can be used for total instance )
ram_allocation_ratio = 2.0
( double of Total memory can be used for total instance
restart nova and nova-scheduler in all the compute node
systemctl restart openstack-nova-*
systemctl restart openstack-nova-scheduler.service