device: 0.951
vnc: 0.878
other: 0.875
assembly: 0.867
graphic: 0.839
instruction: 0.823
socket: 0.771
mistranslation: 0.726
semantic: 0.712
network: 0.640
boot: 0.632
KVM: 0.449

formating vdi-disk over nbd fails

Hi,
after creating a vdi-image with qemu-vdi and attaching it with qemu-nbd partitioning works fine, but the system hangs up during formating with mkfs.ext4.

Same procedure with qcow2-image works fine 
Tested on Fedora 31 kernel  5.5.7-200.fc31.x86_64


-----------------
#! /bin/sh

qemu-img create -f qcow2 ~/test.qcow2 32G
#qemu-img version 4.1.1 (qemu-4.1.1-1.fc31)

modprobe nbd max_part=8
qemu-nbd --connect=/dev/nbd2 ~/test.qcow2
#qemu-nbd 4.1.1 (qemu-4.1.1-1.fc31)

parted -s /dev/nbd2 "mklabel gpt"
parted -s -a optimal /dev/nbd2 "mkpart test ext4 2048 32G "
parted  -s -a optimal /dev/nbd2 "p"

mkfs.ext4 /dev/nbd2p1
#Format hangs up due to IO errors.
#Tested on Fedora 31, kernel 5.5.7-200.fc31.x86_64

mkdir /mnt/test_qcow2

mount /dev/nbd2p1 /mnt/test_qcow2
df -H

-------------------
#! /bin/sh

qemu-img create -f vdi ~/test.vdi 32G

modprobe nbd max_part=8
qemu-nbd --connect=/dev/nbd4 ~/test.vdi

parted -s /dev/nbd4 "mklabel gpt"
parted -s -a optimal /dev/nbd4 "mkpart test ext4 2048 32G "
parted  -s -a optimal /dev/nbd4 "p"

mkfs.ext4 /dev/nbd4p1
#Format hangs up due to IO errors 
#Tested on Fedora 31 kernel  5.5.7-200.fc31.x86_64

mkdir /mnt/test_vdi

mount /dev/nbd4p1 /mnt/test_vdi
df -H
----------------------


Kind regards
  Eilert

PS.: There may be a connection to this bug:
​ 	
#1661758 qemu-nbd causes data corruption in VDI-format disk images



The QEMU project is currently moving its bug tracking to another system.
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closed already. Thus we are setting older bugs to "Incomplete" now.

If you still think this bug report here is valid, then please switch
the state back to "New" within the next 60 days, otherwise this report
will be marked as "Expired". Or please mark it as "Fix Released" if
the problem has been solved with a newer version of QEMU already.

Thank you and sorry for the inconvenience.


[Expired for QEMU because there has been no activity for 60 days.]