With recent libvirt it is not possible to create a domain where 2 virtual disks backed by the same image share the same serial number. I guess it is because of bug 1245013. But there is a strong use case for it - testing multipath storage setup without requiring external, possibly expensive, multipath capable storage, read for example http://sharkcz.livejournal.com/12846.html It still works in libvirt-1.2.18.1-2.fc22 but not in libvirt-1.3.3.1-3.fc24
Agreed, that is a valid use case and libvirt should not have tried to block it. We should revert all the patches from that referenced bug.
CCing pkrempa who provided the patches for bug 1245013
Maybe it's just some logic missing to allow "my" use case, but still provide higher safety for regular users.
It is generally not libvirt's job to impose policy decisions like this, unless it is functionally required by the virtualization layer. Even in real physical hardware you can attach 2 disks with the same serial - i've had cheap USB HDDs which did this.
I agree. I wasn't aware of the necessity to have identical IDs. Since it doesn't pose any problems I've reverted both the serial and WWN check: commit 5da28cc3069b573f54f0bcaf8eb75476bcfdc6e9 Author: Peter Krempa <pkrempa> Date: Fri Jun 24 17:01:27 2016 +0200 conf: Allow disks with identical WWN or serial Disallowing them broke a use case of testing multipath configurations for storage. Originally this was added as it was impossible to use certain /dev/disk-by... links but the disks worked properly.
libvirt-1.3.3.2-1.fc24 has been submitted as an update to Fedora 24. https://bodhi.fedoraproject.org/updates/FEDORA-2016-65cc608ebe
libvirt-1.3.3.2-1.fc24 has been pushed to the Fedora 24 testing repository. If problems still persist, please make note of it in this bug report. See https://fedoraproject.org/wiki/QA:Updates_Testing for instructions on how to install test updates. You can provide feedback for this update here: https://bodhi.fedoraproject.org/updates/FEDORA-2016-65cc608ebe
libvirt-1.3.3.2-1.fc24 has been pushed to the Fedora 24 stable repository. If problems still persist, please make note of it in this bug report.