Re: [PATCH v2 1/2] qemu-img: Add --target-is-zero to convert

[Eric Blake]

On 2/3/20 12:20 PM, Vladimir Sementsov-Ogievskiy wrote:
> 24.01.2020 13:34, David Edmondson wrote:
> > In many cases the target of a convert operation is a newly provisioned
> > target that the user knows is blank (filled with zeroes). In this
> > situation there is no requirement for qemu-img to wastefully zero out
> > the entire device.
> >
> > Add a new option, --target-is-zero, allowing the user to indicate that
> > an existing target device is already zero filled.
>
> Hi! qemu-img.c part looks OK for me, but other doesn't apply on master now.

Correct. Patch 2/2 is now obsolete and no longer necessary, and patch 1 
needs some tweaks now that we don't have qemu-img.texi.

> I like this thing, and I'd like to make similar option for backup job.

My followup patches to add an all-zero bit to qcow2 are also useful in 
this regard.

--
Eric Blake, Principal Software Engineer
Red Hat, Inc.           +1-919-301-3226
Virtualization:  qemu.org | libvirt.org