OpenStack Compute Error – No compute node record for host [Solved]

OpenStack compute Error: Though the compute hosts had nova-compute service listening, those nodes were not displayed when ‘nova hypervisor-list‘ command was executed.

# nova hypervisor-list
+----+----------------------------+-------+---------+
| ID | Hypervisor hostname | State | Status |
+----+----------------------------+-------+---------+

But the command nova service-list didn’t have any problem in displaying the compute hosts. Well, the issue might sound little strange, but if you are stuck with a similar problem in OpenStack, then here’s the solution.

Solution:

How to fix OpenStack Compute Error – No compute node record for host?

openstack compute error

Step 1: Since the compute hosts are not listed, the issue is related to nova-compute service. So I started to debug the issue right from the logs of nova @ compute nodes.

[compute-node]# cd /var/log/nova
[compute-node]# tailf nova-compute.log

Sample output:

ERROR nova.compute.manager [req-1d2c4e83-a57d-4e66-b8b4-81da4772b0d2 - - - - -] No compute node record for host cloudsecurity5
 INFO nova.compute.resource_tracker [req-1d2c4e83-a57d-4e66-b8b4-81da4772b0d2 - - - - -] Auditing locally available compute resources for node cloudsecurity5
 ERROR nova.compute.manager [req-1d2c4e83-a57d-4e66-b8b4-81da4772b0d2 - - - - -] Error updating resources for node cloudsecurity5

The above error indicates that the OpenStack scheduler is not able to find suitable compute host – probably due to invalid hypervisor or nova-compute service is not up or other configuration issue.

Step 2: Verify the configurations of Nova Compute

[compute-node]# vim /etc/nova-compute.conf

and look out for the below entries under [DEFAULT] section.

 [DEFAULT]
 compute_driver=libvirt.LibvirtDriver
 [libvirt]
 virt_type=kvm

Also ensure /etc/nova/nova.conf has all necessary configurations to run a compute host.

The central part of nova-compute service is the virtualization driver that interface with hypervisor. OpenStack supports many compute drivers such as libvirt.LibvirtDriver for KVM , xenapi.XenAPIDriver for Xen, vmwareapi.VMwareVCDriver for VMware and hyperv.HyperVDrive for HyperV. In my case, I was using libvirt compute driver (lookout for compute_driver attribute in the above snapshot).

Step 3: Ensure libvirt daemon is running.

[compute-node]# /etc/init.d/libvirt-bin status

Fortunately, the service libvirt-bin was active, but I did saw few errors at the end of the status output as shown below:

cloudsecurity5 libvirtd[58988]: hostname: cloudsecurity5.test.in
 cloudsecurity5 libvirtd[58988]: End of file while reading data: Input/output error

Though libvirt-bin daemon was running, it still indicates an issue while performing an Input/Output operations.

Hence, I decided to restart libvirt-bin and its related daemon called libvirt-guests.

[compute-node]# /etc/init.d/libvirt-guests restart
[compute-node]# /etc/init.d/libvirt-bin restart

Once done, confirm if the daemon is running without any error.

[compute-node]# /etc/init.d/libvirt-bin status

Sample output at the end of the service status message:

cloudsecurity2 systemd[1]: Starting Virtualization daemon...
 cloudsecurity2 systemd[1]: Started Virtualization daemon.
 cloudsecurity2 dnsmasq[2960]: read /etc/hosts - 9 addresses
 cloudsecurity2 dnsmasq[2960]: read /var/lib/libvirt/dnsmasq/def
 cloudsecurity2 dnsmasq-dhcp[2960]: read /var/lib/libvirt/dnsmas

Step 4: Restart nova-compute service as well.

[compute-node]# /etc/init.d/nova-compute restart

In my case, libvirt daemon’s Input/Output error was the culprit. The issue is solved and now the compute nodes are registered properly as shown below:

# nova hypervisor-list
 +----+----------------------------+-------+---------+
 | ID | Hypervisor hostname | State | Status |
 +----+----------------------------+-------+---------+
 | 1 | cloudsecurity5.test.in | up | enabled |
 +----+----------------------------+-------+---------+

 


Related Content
vps germany
Disclaimer: The content published in this article is the views of the author only. Techglimpse does not gurantee accuracy, completness or validity. If you believe the content on this post violates your copyright, please send us a mail for removal. Read more.