[virt-tools-list] RFC: virt-manager feature removals

[Povilas Kanapickas]

Hi all,

On 2019-06-22 02:14, Cole Robinson wrote:
> On 6/19/19 6:34 PM, Cole Robinson wrote:
> <...>
> 
> * console scaling options (always, never, fullscreen): we've had this in
> the UI forever, but I don't think it has much usage. virt-viewer doesn't
> even expose it how we do, instead it just has a zoom option which I
> don't think we need to implement either. just today there was a bug
> reported saying that scale->always is fairly obviously broken and has
> been for a few releases, which makes me think no one is using it.
> dropping this could be part of a larger think of how console sizing
> works, if we should default to spice auto-resize, or if there's some
> more modern config we should be taking care of.
> https://bugzilla.redhat.com/show_bug.cgi?id=1722088

I would like to voice a use case for which scaling is important: when
the guest and the host have completely different ideas of what the dpi
is. I personally used "always" scaling frequently when to a low-dpi VM
from a high-dpi laptop. The "never" scaling option is useful whenever
the resolution is not very high as some users may want crisp fonts.

Unrelatedly, is there any usage data collected from within virt-manager?
In my experience it's very hard to correctly guess how popular a feature
is, so this feature could eventually be really useful to decide what
features to keep and what to drop.

> * disk: performance options: cache setting seems to be common enough
> that we should keep it. io threads vs native is rarely changed in
> my experience, our default seems good enough, so it's fine to drop.
> discard mode and detect zeroes I'm unsure about. they are fairly new
> to the UI. discard mode is definitely something people inquire about
> setting, I feel like we should have a discussion about whether setting
> this by default makes sense. detect zeroes I don't hear much
> about but I wonder as well if it's possible to set as a default
It's unfortunate that people don't know about discard mode and detect
zeroes options. It's the only way I know that allows reducing qemu disk
image sizes to what is offered by e.g. Virtualbox. Unfortunately qemu
still does a bad job in optimizing zeroed-out disk space, but at least
it will be possible to reap the benefits as soon as the bugs are fixed.

Regards,
Povilas