Troubleshooting Ironic¶

Nova returns “No valid host was found” Error¶

Sometimes Nova Conductor log file “nova-conductor.log” or a message returned from Nova API contains the following error:

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

“No valid host was found” means that the Nova Scheduler could not find a bare metal node suitable for booting the new instance.

This in turn usually means some mismatch between resources that Nova expects to find and resources that Ironic advertised to Nova.

A few things should be checked in this case:

1. Make sure that enough nodes are in available state, not in maintenance mode and not already used by an existing instance. Check with the following command:

   ironic node-list --provision-state available --maintenance false --associated false
   

   If this command does not show enough nodes, use generic ironic node-list to check other nodes. For example, nodes in manageable state should be made available:

   ironic node-set-provision-state <IRONIC NODE> provide
   

   The Bare metal service automatically puts a node in maintenance mode if there are issues with accessing its management interface. Check the power credentials (e.g. ipmi_address, ipmi_username and ipmi_password) and then move the node out of maintenance mode:

   ironic node-set-maintenance <IRONIC NODE> off
   

   The node-validate command can be used to verify that all required fields are present. The following command should not return anything:

   ironic node-validate baremetal-0 | grep -E '(power|management)\W*False'
   

   Maintenance mode will be also set on a node if automated cleaning has failed for it previously.

2. Starting with the Pike release, check that all your nodes have the resource_class field set using the following command:

   openstack --os-baremetal-api-version 1.21 baremetal node list --fields uuid name resource_class
   

   Then check that the flavor(s) are configured to request these resource classes via their properties:

   openstack flavor show <FLAVOR NAME> -f value -c properties
   

   For example, if your node has resource class baremetal-large, it will be matched by a flavor with property resources:CUSTOM_BAREMETAL_LARGE set to 1. See Create flavors for use with the Bare Metal service for more details on the correct configuration.

3. If you do not use scheduling based on resource classes, then the node’s properties must have been set either manually or via inspection. For each node with available state check that the properties JSON field has valid values for the keys cpus, cpu_arch, memory_mb and local_gb. Example of valid properties:

   $ ironic node-show <IRONIC NODE> --fields properties
   +------------+------------------------------------------------------------------------------------+
   | Property   | Value                                                                              |
   +------------+------------------------------------------------------------------------------------+
   | properties | {u'memory_mb': u'8192', u'cpu_arch': u'x86_64', u'local_gb': u'41', u'cpus': u'4'} |
   +------------+------------------------------------------------------------------------------------+
   

   Warning

   If you’re using exact match filters in the Nova Scheduler, make sure the flavor and the node properties match exactly.

4. The Nova flavor that you are using does not match any properties of the available Ironic nodes. Use

   openstack flavor show <FLAVOR NAME>
   

   to compare. The extra specs in your flavor starting with capability: should match ones in node.properties['capabilities'].

   Note

   The format of capabilities is different in Nova and Ironic. E.g. in Nova flavor:

   $ openstack flavor show <FLAVOR NAME> -c properties
   +------------+----------------------------------+
   | Field      | Value                            |
   +------------+----------------------------------+
   | properties | capabilities:boot_option='local' |
   +------------+----------------------------------+
   

   But in Ironic node:

   $ ironic node-show <IRONIC NODE> --fields properties
   +------------+-----------------------------------------+
   | Property   | Value                                   |
   +------------+-----------------------------------------+
   | properties | {u'capabilities': u'boot_option:local'} |
   +------------+-----------------------------------------+
   

5. After making changes to nodes in Ironic, it takes time for those changes to propagate from Ironic to Nova. Check that

   openstack hypervisor stats show
   

   correctly shows total amount of resources in your system. You can also check openstack hypervisor show <IRONIC NODE> to see the status of individual Ironic nodes as reported to Nova.

6. Figure out which Nova Scheduler filter ruled out your nodes. Check the nova-scheduler logs for lines containing something like:

   Filter ComputeCapabilitiesFilter returned 0 hosts
   

   The name of the filter that removed the last hosts may give some hints on what exactly was not matched. See Nova filters documentation for more details.

7. If none of the above helped, check Ironic conductor log carefully to see if there are any conductor-related errors which are the root cause for “No valid host was found”. If there are any “Error in deploy of node <IRONIC-NODE-UUID>: [Errno 28] …” error messages in Ironic conductor log, it means the conductor run into a special error during deployment. So you can check the log carefully to fix or work around and then try again.

Patching the Deploy Ramdisk¶

When debugging a problem with deployment and/or inspection you may want to quickly apply a change to the ramdisk to see if it helps. Of course you can inject your code and/or SSH keys during the ramdisk build (depends on how exactly you’ve built your ramdisk). But it’s also possible to quickly modify an already built ramdisk.

Create an empty directory and unpack the ramdisk content there:

mkdir unpack
cd unpack
gzip -dc /path/to/the/ramdisk | cpio -id

The last command will result in the whole Linux file system tree unpacked in the current directory. Now you can modify any files you want. The actual location of the files will depend on the way you’ve built the ramdisk.

After you’ve done the modifications, pack the whole content of the current directory back:

find . | cpio -H newc -o > /path/to/the/new/ramdisk

API Errors¶

The debug_tracebacks_in_api config option may be set to return tracebacks in the API response for all 4xx and 5xx errors.

Retrieving logs from the deploy ramdisk¶

When troubleshooting deployments (specially in case of a deploy failure) it’s important to have access to the deploy ramdisk logs to be able to identify the source of the problem. By default, Ironic will retrieve the logs from the deploy ramdisk when the deployment fails and save it on the local filesystem at /var/log/ironic/deploy.

To change this behavior, operators can make the following changes to /etc/ironic/ironic.conf under the [agent] group:

• deploy_logs_collect: Whether Ironic should collect the deployment logs on deployment. Valid values for this option are:
  • on_failure (default): Retrieve the deployment logs upon a deployment failure.
  • always: Always retrieve the deployment logs, even if the deployment succeed.
  • never: Disable retrieving the deployment logs.
• deploy_logs_storage_backend: The name of the storage backend where the logs will be stored. Valid values for this option are:
  • local (default): Store the logs in the local filesystem.
  • swift: Store the logs in Swift.
• deploy_logs_local_path: The path to the directory where the logs should be stored, used when the deploy_logs_storage_backend is configured to local. By default logs will be stored at /var/log/ironic/deploy.
• deploy_logs_swift_container: The name of the Swift container to store the logs, used when the deploy_logs_storage_backend is configured to “swift”. By default ironic_deploy_logs_container.
• deploy_logs_swift_days_to_expire: Number of days before a log object is marked as expired in Swift. If None, the logs will be kept forever or until manually deleted. Used when the deploy_logs_storage_backend is configured to “swift”. By default 30 days.

When the logs are collected, Ironic will store a tar.gz file containing all the logs according to the deploy_logs_storage_backend configuration option. All log objects will be named with the following pattern:

<node-uuid>[_<instance-uuid>]_<timestamp yyyy-mm-dd-hh:mm:ss>.tar.gz

$ ls /var/log/ironic/deploy | grep 5e9258c4-cfda-40b6-86e2-e192f523d668
5e9258c4-cfda-40b6-86e2-e192f523d668_88595d8a-6725-4471-8cd5-c0f3106b6898_2016-08-08-13:52:12.tar.gz
5e9258c4-cfda-40b6-86e2-e192f523d668_db87f2c5-7a9a-48c2-9a76-604287257c1b_2016-08-08-14:07:25.tar.gz

$ swift list ironic_deploy_logs_container -p 5e9258c4-cfda-40b6-86e2-e192f523d668
5e9258c4-cfda-40b6-86e2-e192f523d668_88595d8a-6725-4471-8cd5-c0f3106b6898_2016-08-08-13:52:12.tar.gz
5e9258c4-cfda-40b6-86e2-e192f523d668_db87f2c5-7a9a-48c2-9a76-604287257c1b_2016-08-08-14:07:25.tar.gz

$ swift download ironic_deploy_logs_container "5e9258c4-cfda-40b6-86e2-e192f523d668_db87f2c5-7a9a-48c2-9a76-604287257c1b_2016-08-08-14:07:25.tar.gz"
5e9258c4-cfda-40b6-86e2-e192f523d668_db87f2c5-7a9a-48c2-9a76-604287257c1b_2016-08-08-14:07:25.tar.gz [auth 0.341s, headers 0.391s, total 0.391s, 0.531 MB/s]

$ tar xvf <file path>

$ tar xvf 5e9258c4-cfda-40b6-86e2-e192f523d668_88595d8a-6725-4471-8cd5-c0f3106b6898_2016-08-08-13:52:12.tar.gz
df
ps
journal
ip_addr
iptables

DHCP during PXE or iPXE is inconsistent or unreliable¶

This can be caused by the spanning tree protocol delay on some switches. The delay prevents the switch port moving to forwarding mode during the nodes attempts to PXE, so the packets never make it to the DHCP server. To resolve this issue you should set the switch port that connects to your baremetal nodes as an edge or PortFast type port. Configured in this way the switch port will move to forwarding mode as soon as the link is established. An example on how to do that for a Cisco Nexus switch is:

$ config terminal
$ (config) interface eth1/11
$ (config-if) spanning-tree port type edge