Recreated setup, pre-fix the error triggers: root@b:~# virsh attach-device b-testattach controller_scsi.xml --persistent error: Failed to attach device from controller_scsi.xml error: internal error: Cannot parse controller index -1 root@b:~# virsh attach-device b-testattach controller_scsi.xml --live --config error: Failed to attach device from controller_scsi.xml error: internal error: Cannot parse controller index -1 Installing from proposed: root@b:~# apt update Hit:1 http://archive.ubuntu.com/ubuntu bionic InRelease Hit:2 http://security.ubuntu.com/ubuntu bionic-security InRelease Hit:3 http://archive.ubuntu.com/ubuntu bionic-updates InRelease Hit:4 http://archive.ubuntu.com/ubuntu bionic-backports InRelease Hit:5 http://archive.ubuntu.com/ubuntu bionic-proposed InRelease Reading package lists... Done Building dependency tree Reading state information... Done 7 packages can be upgraded. Run 'apt list --upgradable' to see them. root@b:~# apt upgrade Reading package lists... Done Building dependency tree Reading state information... Done Calculating upgrade... Done The following packages will be upgraded: libvirt-clients libvirt-daemon libvirt-daemon-driver-storage-rbd libvirt-daemon-system libvirt0 netplan.io nplan 7 upgraded, 0 newly installed, 0 to remove and 0 not upgraded. Need to get 62.3 kB/4177 kB of archives. After this operation, 12.3 kB of additional disk space will be used. Do you want to continue? [Y/n] Y Get:1 http://archive.ubuntu.com/ubuntu bionic-proposed/main amd64 netplan.io amd64 0.96-0ubuntu0.18.04.4 [60.5 kB] Get:2 http://archive.ubuntu.com/ubuntu bionic-proposed/main amd64 nplan all 0.96-0ubuntu0.18.04.4 [1792 B] Fetched 62.3 kB in 0s (613 kB/s) Preconfiguring packages ... (Reading database ... 52646 files and directories currently installed.) Preparing to unpack .../0-libvirt-daemon-system_4.0.0-1ubuntu8.9_amd64.deb ... Unpacking libvirt-daemon-system (4.0.0-1ubuntu8.9) over (4.0.0-1ubuntu8.8) ... Preparing to unpack .../1-libvirt-clients_4.0.0-1ubuntu8.9_amd64.deb ... Unpacking libvirt-clients (4.0.0-1ubuntu8.9) over (4.0.0-1ubuntu8.8) ... Preparing to unpack .../2-libvirt-daemon-driver-storage-rbd_4.0.0-1ubuntu8.9_amd64.deb ... Unpacking libvirt-daemon-driver-storage-rbd (4.0.0-1ubuntu8.9) over (4.0.0-1ubuntu8.8) ... Preparing to unpack .../3-libvirt-daemon_4.0.0-1ubuntu8.9_amd64.deb ... Unpacking libvirt-daemon (4.0.0-1ubuntu8.9) over (4.0.0-1ubuntu8.8) ... Preparing to unpack .../4-libvirt0_4.0.0-1ubuntu8.9_amd64.deb ... Unpacking libvirt0:amd64 (4.0.0-1ubuntu8.9) over (4.0.0-1ubuntu8.8) ... Preparing to unpack .../5-netplan.io_0.96-0ubuntu0.18.04.4_amd64.deb ... Unpacking netplan.io (0.96-0ubuntu0.18.04.4) over (0.96-0ubuntu0.18.04.3) ... Preparing to unpack .../6-nplan_0.96-0ubuntu0.18.04.4_all.deb ... Unpacking nplan (0.96-0ubuntu0.18.04.4) over (0.96-0ubuntu0.18.04.3) ... Processing triggers for ureadahead (0.100.0-21) ... Setting up libvirt0:amd64 (4.0.0-1ubuntu8.9) ... Setting up netplan.io (0.96-0ubuntu0.18.04.4) ... Setting up libvirt-daemon (4.0.0-1ubuntu8.9) ... Processing triggers for libc-bin (2.27-3ubuntu1) ... Setting up nplan (0.96-0ubuntu0.18.04.4) ... Processing triggers for systemd (237-3ubuntu10.21) ... Processing triggers for man-db (2.8.3-2ubuntu0.1) ... Setting up libvirt-clients (4.0.0-1ubuntu8.9) ... Setting up libvirt-daemon-system (4.0.0-1ubuntu8.9) ... virtlockd.service is a disabled or a static unit, not starting it. Setting up libvirt-daemon dnsmasq configuration. Setting up libvirt-daemon-driver-storage-rbd (4.0.0-1ubuntu8.9) ... That worked fine, now test the bug root@b:~# virsh attach-device b-testattach controller_scsi.xml --persistent Device attached successfully root@b:~# virsh attach-device b-testattach controller_scsi.xml --live --config Device attached successfully Please note that detaching it the same way "correctly" complains about the missing index. It can't identify the controller to detach which isn't required for attach. A fully specified device detaches just fine root@b:~# cat controller_scsi2.xml
root@b:~# virsh detach-device b-testattach controller_scsi2.xml Device detached successfully Setting bug to verification complete