Common Errors and Fixes for OpenStack Compute

The Launchpad Answers site offers a place to ask and answer questions, and you can also mark questions as frequently asked questions.

Credential errors, 401, 403 forbidden errors

A 403 forbidden error is caused by missing credentials. Through current installation methods, there are basically two ways to get the novarc file. The manual method requires getting it from within a project zipfile, and the scripted method just generates novarc out of the project zip file and sources it for you. If you do the manual method through a zip file, then the following novarc alone, you end up losing the creds that are tied to the user you created with nova-manage in the steps before.

When you run nova-api the first time, it generates the certificate authority information, including openssl.cnf. If it gets started out of order, you may not be able to create your zip file. Once your CA information is available, you should be able to go back to nova-manage to create your zipfile.

You may also need to check your proxy settings to see if they are causing problems with the novarc creation.

Instance errors

Sometimes a particular instance shows “pending” or you cannot SSH to it. Sometimes the image itself is the problem. For example, when using flat manager networking, you do not have a dhcp server, and an ami-tiny image doesn’t support interface injection so you cannot connect to it. The fix for this type of problem is to use an Ubuntu image, which should obtain an IP address correctly with FlatManager network settings. To troubleshoot other possible problems with an instance, such as one that stays in a spawning state, first check your instances directory for i-ze0bnh1q dir to make sure it has the following files:

  • libvirt.xml
  • disk
  • disk-raw
  • kernel
  • ramdisk
  • console.log (Once the instance actually starts you should see a console.log.)

Check the file sizes to see if they are reasonable. If any are missing/zero/very small then nova-compute has somehow not completed download of the images from objectstore.

Also check nova-compute.log for exceptions. Sometimes they don’t show up in the console output.

Next, check the /var/log/libvirt/qemu/i-ze0bnh1q.log file to see if it exists and has any useful error messages in it.

Finally, from the instances/i-ze0bnh1q directory, try virsh create libvirt.xml and see if you get an error there.

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