One further note for debugging. If you look at the web request log (somewhere in /var/log/maas), you can see the constraints requested by the juju maas provider to maas itself in the HTTP query string. This could help pin it down - especially to check if it is really only the cpu parameter that changed from maas' point of view.
** Changed in: maas (Ubuntu) Status: New => Incomplete -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1154803 Title: Constraints prevents the allocation of nodes if they are equal to the HW. To manage notifications about this bug go to: https://bugs.launchpad.net/maas/+bug/1154803/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs