Description of problem: When the variable max_disk_devices_to_attach is set to 0 (documentation indicates it accepts >=0) it won't allow to create any instances in any compute node. This will prevent customer of creating any instance. Version-Release number of selected component (if applicable): openstack-nova-compute:16.0-80 How reproducible: set the max_disk_devices_to_attach to 0 in nova.conf and create any instance Steps to Reproduce: 1- Create a yaml file containing: parameter_defaults: ComputeExtraConfig: nova::config::nova_config: compute/max_disk_devices_to_attach: value: '"0"' 2- Deploy the overcloud 3- Create an instance Actual results: Instance is not created. The following error message appears: 'code': 500, 'created': '2020-02-11T19:54:07Z', 'message': 'Build of instance a43020ca-de89-4082-9beb-52cefe9905a6 aborted: The maximum allowed number of disk devices (0) to attach to a single instance has been exceeded.' Expected results: - Instance to be created with at least one root device to allow boot. OR - Indicate in the documentation that allowed values are (-1) and >=1 with the side effect of setting it to zero Additional info:
Here's a link to our existing documentation around the max_disk_devices_to_attach config option: https://access.redhat.com/documentation/en-us/red_hat_openstack_platform/15/html-single/advanced_overcloud_customization/index#sect-Config_max_disk_devices_to_attach
Since the problem described in this bug report should be resolved in a recent advisory, it has been closed with a resolution of ERRATA. For information on the advisory (Release of components for Red Hat OpenStack Platform 17.0 (Wallaby)), and where to find the updated files, follow the link below. If the solution does not work for you, open a new bug report. https://access.redhat.com/errata/RHEA-2022:6543