OpenStack – NoValidHost: No valid host was found


When creating a new instance within OpenStack you observe the following error,

==> /var/log/nova/nova-conductor.log <==
... u"RescheduledException: Build of instance xxx-yyy-zzz was re-scheduled: internal error: no 
supported architecture for os type 'hvm'\n"]
... NoValidHost: No valid host was found. There are not enough hosts available.


This due to running OpenStack within a virtual machine. As on the compute host you are trying to run KVM but the virtualisation extensions KVM require are not available.

To resolve the issue edit your /etc/nova/nova.conf to use qemu.

Rick Donato

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