VM failed to start qemu-kvm: -blockdev

Hi,

I’m running a VM on RedHat. Seems that a the source of my problem is: is “rather nasty – qemu update to version 6 has changed compatibility (see here) and libvirt has not followed through.”

Was able to partially fix my issue by:
“An ugly workaround is to modify the XML directly (either using Virt-Manager or using text editor of the VM’s XML) and modify the disk to the following. Change ‘file’ into ‘block’ as the type, and change source from ‘file’ type to ‘dev’ type.” qemu-kvm: file driver requires to be a regular file for ZFS volume - Running Systems

Remaining error I can’t fix is:
internal error: process exited while connecting to monitor: 2022-11-05T00:11:40.702330Z qemu-kvm: -blockdev {“driver”:“file”,“filename”:“/dev/sdb”,“node-name”:“libvirt-2-storage”,“auto-read-only”:true,“discard”:“unmap”}: ‘file’ driver requires ‘/dev/sdb’ to be a regular file

[xxxxxx@localhost ~]$ getfacl /dev/sdb
getfacl: Removing leading ‘/’ from absolute path names

file: dev/sdb

owner: root

group: disk

user::rw-
group::rw-
other::—

I tried the following command but can’t make it work:
setfacl -m u:libvirt-qemu:x /dev/sdb (setfacl: Option -m: Invalid argument near character 3)

Bit of a noob here and looking for help

Cheers
John

just adding XML from VM if this helps. Any help is very welcome.

  <driver name='qemu' type='qcow2'/>


  <source file='/var/lib/libvirt/images/ZFS.qcow2'/>


  <backingStore/>


  <target dev='hda' bus='ide'/>


  <address type='drive' controller='0' bus='0' target='0' unit='0'/>


</disk>


<disk type='file' device='cdrom'>


  <driver name='qemu' type='raw'/>


  <target dev='hdb' bus='ide'/>


  <readonly/>


  <address type='drive' controller='0' bus='0' target='0' unit='1'/>


</disk>


<disk type='block' device='disk'>


  <driver name='qemu' type='raw'/>


  <source dev='/dev/sdb'/>


  <target dev='vda' bus='virtio'/>


  <address type='pci' domain='0x0000' bus='0x00' slot='0x09' function='0x0'/>


</disk>


<disk type='block' device='disk'>


  <driver name='qemu' type='raw'/>


  <source dev='/dev/sdc'/>


  <target dev='vdb' bus='virtio'/>


  <address type='pci' domain='0x0000' bus='0x00' slot='0x08' function='0x0'/>


</disk>


<controller type='usb' index='0' model='ich9-ehci1'>


  <address type='pci' domain='0x0000' bus='0x00' slot='0x05' function='0x7'/>


</controller>


<controller type='usb' index='0' model='ich9-uhci1'>


  <master startport='0'/>


  <address type='pci' domain='0x0000' bus='0x00' slot='0x05' function='0x0' multifunction='on'/>


</controller>


<controller type='usb' index='0' model='ich9-uhci2'>


  <master startport='2'/>


  <address type='pci' domain='0x0000' bus='0x00' slot='0x05' function='0x1'/>


</controller>


<controller type='usb' index='0' model='ich9-uhci3'>


  <master startport='4'/>


  <address type='pci' domain='0x0000' bus='0x00' slot='0x05' function='0x2'/>


</controller>


<controller type='pci' index='0' model='pci-root'/>


<controller type='ide' index='0'>


  <address type='pci' domain='0x0000' bus='0x00' slot='0x01' function='0x1'/>


</controller>


<controller type='virtio-serial' index='0'>


  <address type='pci' domain='0x0000' bus='0x00' slot='0x06' function='0x0'/>


</controller>