[Qemu-discuss] qemu-img and qcow2 disk size problem

[Skardal, Harald]

All,

 

First question to the list, so let me know if there is a more appropriate forum for these questions:

 

Platform: Fedora-virt-preview from a couple of weeks back with qemu 1.3.0-9:

 

address@hidden are]# rpm --query --file /usr/bin/qemu-img

qemu-img-1.3.0-9.fc18.x86_64

address@hidden are]#

 

With qemu-img, have created a qcow2 file of size 9.7GB.

 

image: /var/lib/libvirt/images/hsdr01d.d0.img

file format: qcow2

virtual size: 9.7G (10450108416 bytes)

disk size: 136K

cluster_size: 65536

 

I attach this qcow2 disk successfully:

 

address@hidden ~]# virsh attach-disk are1 /var/lib/libvirt/images/hsdr01d.d0.img vdb

Disk attached successfully

 

address@hidden

 

I go inside the guest and look at the disk:

 

address@hidden are]# fdisk -l /dev/vdb

 

Disk /dev/vdb: 1559 MB, 1559322624 bytes, 3045552 sectors

Units = sectors of 1 * 512 = 512 bytes

Sector size (logical/physical): 512 bytes / 512 bytes

I/O size (minimum/optimal): 512 bytes / 512 bytes

 

address@hidden are]#

 

I know this qcow2 disk is /dev/vdb because before the attach /dev/vdb was not there.

 

The issue: The disk that the guest sees is only 1.5 GB, which is where my writes stop with a write failure.

 

How do I attach this qcow2 disk in such a way that the guest can see the full virtual size?

Is there anything in the create or attach command that I am missing?

 

I was going to use nbd on the host, but there is a missing symbol in the version in the repo ….

 

      Harald