Public bug reported: This is a bug to track the addition of a note to the config option help for [compute]max_disk_devices_to_attach. An issue was raised downstream [1] around the fact that setting this option to 0 will cause instances not to boot because they will be allowed 0 disk devices.
The CONF.max_disk_devices_to_attach option controls the maximum number of disk devices allowed to attach to an instance. If it is set to 0, it will literally allow no disk device for instances, preventing them from being able to boot. There doesn't appear to be any way to disallow particular values in a oslo.config IntOpt other than the min/max values. Here we need the min value to be -1 to represent unlimited. There is a 'choices' kwarg available but that is only for enumerating valid values and we need to allow any integer >= 1 as well. Finally, there doesn't seem to be a good way to validate this option setting as -1 or >= 1 because it's a nova-compute config option and our choices there are likely: prevent nova-compute from starting because of value 0 or log a WARNING about it, both of which seem like they might be overkill. So, highlighting the behavior of value 0 in the documentation might be the best way to handle the issue. [1] https://bugzilla.redhat.com/show_bug.cgi?id=1801931 ** Affects: nova Importance: Low Assignee: melanie witt (melwitt) Status: In Progress ** Affects: nova/stein Importance: Undecided Status: New ** Affects: nova/train Importance: Undecided Status: New ** Affects: nova/ussuri Importance: Undecided Status: New ** Affects: nova/victoria Importance: Undecided Status: New ** Tags: doc -- You received this bug notification because you are a member of Yahoo! Engineering Team, which is subscribed to OpenStack Compute (nova). https://bugs.launchpad.net/bugs/1897950 Title: doc: setting [compute]max_disk_devices_to_attach = 0 prevents instances from booting Status in OpenStack Compute (nova): In Progress Status in OpenStack Compute (nova) stein series: New Status in OpenStack Compute (nova) train series: New Status in OpenStack Compute (nova) ussuri series: New Status in OpenStack Compute (nova) victoria series: New Bug description: This is a bug to track the addition of a note to the config option help for [compute]max_disk_devices_to_attach. An issue was raised downstream [1] around the fact that setting this option to 0 will cause instances not to boot because they will be allowed 0 disk devices. The CONF.max_disk_devices_to_attach option controls the maximum number of disk devices allowed to attach to an instance. If it is set to 0, it will literally allow no disk device for instances, preventing them from being able to boot. There doesn't appear to be any way to disallow particular values in a oslo.config IntOpt other than the min/max values. Here we need the min value to be -1 to represent unlimited. There is a 'choices' kwarg available but that is only for enumerating valid values and we need to allow any integer >= 1 as well. Finally, there doesn't seem to be a good way to validate this option setting as -1 or >= 1 because it's a nova-compute config option and our choices there are likely: prevent nova-compute from starting because of value 0 or log a WARNING about it, both of which seem like they might be overkill. So, highlighting the behavior of value 0 in the documentation might be the best way to handle the issue. [1] https://bugzilla.redhat.com/show_bug.cgi?id=1801931 To manage notifications about this bug go to: https://bugs.launchpad.net/nova/+bug/1897950/+subscriptions -- Mailing list: https://launchpad.net/~yahoo-eng-team Post to : yahoo-eng-team@lists.launchpad.net Unsubscribe : https://launchpad.net/~yahoo-eng-team More help : https://help.launchpad.net/ListHelp