+++ This bug was initially created as a clone of Bug #1774375 +++ Based on comment 6 of the bug above. The root cause is completely different. When a disk has copy on read configured qemu reports an error when trying to block-commit. --- Additional comment from Han Han on 2020-01-17 07:40:37 CET --- test failed on libvirt-6.0.0-1.module+el8.2.0+5453+31b2b136.x86_64 qemu-kvm-4.2.0-6.module+el8.2.0+5453+31b2b136.x86_64: Prepare an active vm: # virsh snapshot-create-as pc s1 --no-metadata --disk-only Domain snapshot s1 created # virsh blockcommit pc vda --active --wait --verbose error: internal error: unable to execute QEMU command 'block-commit': Need a root block node # virsh blockcommit pc vda --active --wait --verbose error: internal error: child reported (status=125): Requested operation is not valid: Setting different SELinux label on /var/lib/libvirt/images/RHEL-8.2-x86_64-latest.qcow2 which is already in use # virsh blockcommit pc vda --active --wait --verbose error: internal error: child reported (status=125): Requested operation is not valid: Setting different SELinux label on /var/lib/libvirt/images/RHEL-8.2-x86_64-latest.qcow2 which is already in use
And also https://bugzilla.redhat.com/show_bug.cgi?id=1774375#c9
Created attachment 1653519 [details] XMLs and libvirtd log It also fails at hot-plug: 1. Start an VM 2. Attach a disk with copy_on_read on: # cat disk.xml <disk type='block' device='disk'> <driver name='qemu' type='raw' copy_on_read='on'/> <source dev='/dev/sdb'/> <target dev='vdb' bus='virtio'/> </disk> # virsh attach-device pc disk.xml error: Failed to attach device from disk.xml error: internal error: missing alias or qom-type for qemu object '<null>'
Fixed upstream by: 0c3792a155 qemu: backup: Implement support for backup disk bitmap name configuration bce4ac55f8 qemu: backup: Implement support for backup disk export name configuration 12ccd8d4db conf: backup: Allow configuration of names exported via NBD 69908db0f6 qemu: Fix value of 'device' argument for block-commit e3137539a9 qemu: Fix value of 'device' argument for blockdev-mirror 0b0f389335 qemu: domain: Extract code to determine topmost nodename to qemuDomainDiskGetTopNodename 623366d130 qemu: blockcopy: Actually unplug unused images when mirror job fails to start Note that due to bug 1594747 the block-commit job still will not work but with a different error message. This series also fixes the unplug of the backend on a failed job.
(In reply to Han Han from comment #2) > Created attachment 1653519 [details] > XMLs and libvirtd log > > It also fails at hot-plug: > 1. Start an VM > 2. Attach a disk with copy_on_read on: > # cat disk.xml > <disk type='block' device='disk'> > <driver name='qemu' type='raw' copy_on_read='on'/> > <source dev='/dev/sdb'/> > <target dev='vdb' bus='virtio'/> > </disk> > > # virsh attach-device pc disk.xml > error: Failed to attach device from disk.xml > error: internal error: missing alias or qom-type for qemu object '<null>' Since hot-plug is not a block job, please file a separate bug for that issue.
(In reply to Peter Krempa from comment #4) > (In reply to Han Han from comment #2) > > Created attachment 1653519 [details] > > XMLs and libvirtd log > > > > It also fails at hot-plug: > > 1. Start an VM > > 2. Attach a disk with copy_on_read on: > > # cat disk.xml > > <disk type='block' device='disk'> > > <driver name='qemu' type='raw' copy_on_read='on'/> > > <source dev='/dev/sdb'/> > > <target dev='vdb' bus='virtio'/> > > </disk> > > > > # virsh attach-device pc disk.xml > > error: Failed to attach device from disk.xml > > error: internal error: missing alias or qom-type for qemu object '<null>' > > Since hot-plug is not a block job, please file a separate bug for that issue. New bug: https://bugzilla.redhat.com/show_bug.cgi?id=1798366
Test result: PASS [root@hp-dl320eg8-05 bz1792195]# rpm -qa | egrep "^libvirt-6|^qemu-kvm-4" qemu-kvm-4.2.0-10.module+el8.2.0+5740+c3dff59e.x86_64 libvirt-6.0.0-5.module+el8.2.0+5765+64816f89.x86_64 [root@hp-dl320eg8-05 bz1792195]# virsh start vm1 Domain vm1 started [root@hp-dl320eg8-05 bz1792195]# virsh dumpxml vm1 | awk '/<disk/,/<\/disk/' <disk type='file' device='disk'> <driver name='qemu' type='qcow2' copy_on_read='on'/> <source file='/var/lib/libvirt/images/vda.qcow2' index='1'/> <backingStore/> <target dev='vda' bus='virtio'/> <alias name='virtio-disk0'/> <address type='pci' domain='0x0000' bus='0x04' slot='0x00' function='0x0'/> </disk> [root@hp-dl320eg8-05 bz1792195]# virsh snapshot-create-as vm1 s1 --no-metadata --disk-only Domain snapshot s1 created [root@hp-dl320eg8-05 bz1792195]# virsh blockcommit vm1 vda --active --wait --verbose error: internal error: unable to execute QEMU command 'block-commit': 'libvirt-2-format' is not in this backing file chain The error message is due to copy-on-read broke the backing chain due to bug 1594747 as mentioned in comment 3. So mark current bz as VERIFIED backup scenarios will be covered in IncrementalBackup bz
Since the problem described in this bug report should be resolved in a recent advisory, it has been closed with a resolution of ERRATA. For information on the advisory, and where to find the updated files, follow the link below. If the solution does not work for you, open a new bug report. https://access.redhat.com/errata/RHBA-2020:2017