On Fri, Jun 21, 2024 at 5:48 PM Sven Ott <sven....@fau.de> wrote:
> Hi, I want to mount a VM image to a loop device and give it some excess
> space.
>
> To do so, I download a .qcow2 file, add some 0 bytes with truncate, and
> then convert the image from QCOW2 to RAW format with qemu-img convert,
> like so:
>
> ```
>
> GUEST_IMG=focal-server-cloudimg-amd64
>
> wget https://cloud-images.ubuntu.com/focal/current/$GUEST_IMG
>
> truncate -s 5G $GUEST_IMG.img
>
This is not needed, and ineffective...
>
> qemu-img convert -f qcow2 -O raw $GUEST_IMG.img $GUEST_IMG.raw
>
Since the first thing done in this command is truncating the target image
to 0 bytes.
You can use -n to avoid creation of the target image and use your image,
but this is also not
needed.
You can convert the image:
qemu-img convert -f qccow2 -O raw src.qcow2 dst.raw
and then resize the raw image:
qmeu-img resize dst.raw newsize
You can also resize before converting, it does not matter if you resize
before or after.
Note that you will have to grow the pv/lv/filessystem inside the guest to
use the additional space.
Nir
