The option --image-size does not increase the partition sizes

[Alfonso Sanchez-Beato]

When using the --image-size option, the final size of the image is increased, but the actual partitions inside the disk are kept as if the option had not been provided, leaving empty space in the disk.

This renders the option useless in my opinion. The extra space should be used by the system partition.

[Steve Langasek (vorlon)]

On Fri, Sep 22, 2017 at 07:18:52AM -0000, Alfonso Sanchez-Beato wrote:
> Public bug reported:

> When using the --image-size option, the final size of the image is
> increased, but the actual partitions inside the disk are kept as if the
> option had not been provided, leaving empty space in the disk.

> This renders the option useless in my opinion. The extra space should be
> used by the system partition.

As mentioned in the other bug report, the additional space is used up when
the system partition is expanded at first boot.

For cases where you are dd'ing the image to a physical disk, the option is
not needed. For cases where the image will be loaded by a VM, the option is
certainly needed, in order to give the VM a sane default size to expand
into.

[Alfonso Sanchez-Beato (alfonsosanchezbeato)]

The additional space is useful if you want to chroot into the partition and add stuff, like new packages, before first boot. This is a real use case when creating customized images on top of ubuntu-image output.

[Alfonso Sanchez-Beato (alfonsosanchezbeato)]

This is an old UC16/18 thing and maybe can be closed.

[Paul Mars (upils)]

I am currently globally investigating volume/partition handling in ubuntu-image and it very much looks like there is still several bugs around that. So I will close this once my investigation is done and we are sure u-i is behaving as it should.