Dear all, I am facing an issue while using qemu-nbd thinly-provisioned exported qcow2 disk. below is the steps: 1. qemu-img create -f qcow2 /tmp/img.qcow2 100M 2. qemu-nbd -f raw /tmp/img.qcow2 3. then I use it as a virtual disk in guest vm with xml like below: <disk type='network' device='disk'> <driver name='qemu' type='qcow2'/> <source protocol='nbd'> <host name='xxx.xxx.xxx.xxx' port='10809'/> </source> <target dev='sda' bus='scsi'/> </disk> 4. when i start the guest and try to format it in the guest, I got the error: blk_update_request: critical target error, dev sda, sector 204672 op 0x1:(WRITE) flags 0x800 phys_seg 16 prio class 0
but I tried with the disk image created with full allocated by command: qemu-img create -f qcow2 /tmp/img.qcow2 100M -o preallocation=full then there is no error, so I assume it is related to the thinly-provisioned feature. I am using: qemu-kvm-6.1.0, libvirt-7.8.0 on Red Hat Enterprise Linux release 8.6 Beta So can you kindly help to confirm whether the thinly-provisioned cause the error? and if so, are there any plan to fix or add new feature for it? I am looking forward to your reply, thx.
