semantic: 0.867
graphic: 0.863
other: 0.854
mistranslation: 0.834
assembly: 0.832
KVM: 0.793
instruction: 0.790
device: 0.790
vnc: 0.772
socket: 0.732
boot: 0.709
network: 0.684

qemu-img can not convert virtualbox virtual disk formats qcow

Hello, I'm working with QEMU on macOS, and am experiencing issues working with the `qemu-img` command.

Info
----
$ sw_vers
ProductName:    Mac OS X
ProductVersion: 10.13.6
BuildVersion:   17G4015

VirtualBox
----------
$ VBoxManage --version
6.0.0r127566

$ qemu-system-x86_64 --version
QEMU emulator version 3.1.50 (v3.1.0-rc2-745-g147923b1a9-dirty)
Copyright (c) 2003-2018 Fabrice Bellard and the QEMU Project developers

$ qemu-img --version
qemu-img version 3.1.50 (v3.1.0-rc2-745-g147923b1a9-dirty)
Copyright (c) 2003-2018 Fabrice Bellard and the QEMU Project developers

Steps to reproduce
------------------

> Prereq VirtualBox needs to be installed to run the `VBoxManage` command

$ VBoxManage createmedium disk --filename vbox-vdisk-exp.qcow --format qcow --size 5
0%...10%...20%...30%...40%...50%...60%...70%...80%...90%...100%
Medium created. UUID: e2b36955-3791-4c0e-93d4-913669b1d9fb

$ file vbox-vdisk-exp.qcow
vbox-vdisk-exp.qcow: QEMU QCOW Image (v1), 5242880 bytes

$ qemu-img info vbox-vdisk-exp.qcow
image: vbox-vdisk-exp.qcow
file format: qcow
virtual size: 5.0M (5242880 bytes)
disk size: 8.0K
cluster_size: 4096

# Convert vbox virtualdisk to qcow2 format using `qemu-img`
$ qemu-img convert -f qcow vbox-vdisk-exp.qcow -O qcow2 vbox-vdisk-exp-convert.qcow2

$ file vbox-vdisk-exp-convert.qcow2
vbox-vdisk-exp-convert.qcow2: QEMU QCOW Image (v3), 5242880 bytes

# Print info about qemu-img converted image from vbox created qcow image
$ qemu-img info vbox-vdisk-exp-convert.qcow2                                                   mutts-6 | 0 < 10:53:00
image: vbox-vdisk-exp-convert.qcow2
file format: qcow2
virtual size: 5.0M (5242880 bytes)
disk size: 196K
cluster_size: 65536
Format specific information:
    compat: 1.1
    lazy refcounts: false
    refcount bits: 16
    corrupt: false

# Print info about vbox created qcow image
qemu-img info vbox-vdisk-exp.qcow                                                            mutts-6 | 0 < 10:53:19
image: vbox-vdisk-exp.qcow
file format: qcow
virtual size: 5.0M (5242880 bytes)
disk size: 8.0K
cluster_size: 4096

I've attached a zip file containing the vbox created qcow image along with the image that `qemu-img` converted.



Hi,

What exactly is the issue?  All of that looks rather OK to me.

Max

This bug was related to an IRC discussion on Jan 14th but this bug description is not showing the problem that was raised on IRC. The IRC discussion showed a source image with a 9GB Windows 10 installation, turning into an image with only 8 MB of data present.  The images in this bug description don't have any data written so are not illustrating the data conversion issue.


The QEMU project is currently considering to move its bug tracking to another system. For this we need to know which bugs are still valid and which could be 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 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.]