Re: [libvirt-users] mkfs fails on qemu-nbd device

On Thu, Jun 27, 2019 at 16:22:27 +0530, Tanmoy Sinha wrote:

Hi All,

I am unable to figure out the issue here, when I try to create a filesystem (ext4) on a virtual disk using qemu-nbd. This happens intermittently.

Following is the sequence of commands:-

$> qemu-img create -f qcow2 test.qcow2 30G

$> qemu-nbd --connect=/dev/nbd0 test.qcow2

I think you forgot to use -f qcow2 in this command line. Also the qemu mailing list will probably be better target for this question since your examples are not using libvirt.