> For the complete documentation index, see [llms.txt](https://chameleoncloud.gitbook.io/chi-in-a-box/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://chameleoncloud.gitbook.io/chi-in-a-box/operations/runbooks/instance-failure.md). # Instance Failure Nova can fail to launch instances inside a reservation that clearly still has free nodes. It fails with the error “No valid host found”. This can be caused by multiple reasons: 1. get the list of baremetal nodes in the lease. ``` chameleon lease resource list ``` 2. If a subset of these nodes are failing, then check the specific node: ``` openstack baremetal node show ``` 3. Check if its in maintenance mode 1. If yes, check the reason 4. Check to see if it still has an associated instance ID. If so, run: ``` openstack baremetal node undeploy ``` If these don't show an issue, its time to look at the logs. They can seen in `/var/log/kolla` on your admin node, or via kibana at `:5601` The credentials can be found in your site's ansible-vault If you see a conflict, reference There are also some commands to check the health of all nodes at a site: List all baremetal nodes in maintenance: ``` openstack baremetal node list --maintenance ``` Ironic thinks nodes are active, but doesn’t know about a specific instance ``` openstack baremetal node list --provision-state active --unassociated ``` --- # Agent Instructions This documentation is published with GitBook. GitBook is the documentation platform designed so that both humans and AI agents can read, navigate, and reason over technical content effectively. Learn more at gitbook.com. ## Querying This Documentation If you need additional information that is not directly available in this page, you can query the documentation dynamically by asking a question. Perform an HTTP GET request on the current page URL with the `ask` query parameter, and the optional `goal` query parameter: ``` GET https://chameleoncloud.gitbook.io/chi-in-a-box/operations/runbooks/instance-failure.md?ask=&goal= ``` `ask` is the immediate question: it should be specific, self-contained, and written in natural language. `goal` is optional and describes the broader end goal you are ultimately trying to accomplish on behalf of the user. GitBook uses it to tailor the answer towards what is most useful for that goal. The response will contain a direct answer to the question and relevant excerpts and sources from the documentation. Use this mechanism when the answer is not explicitly present in the current page, you need clarification or additional context, or you want to retrieve related documentation sections.