Re: [PATCH] Document qemu-img options data_file and data_file_raw

[Connor Kuehl]

On 3/26/21 4:24 AM, Max Reitz wrote:
> On 01.03.21 18:28, Connor Kuehl wrote:
> > [..]
> > diff --git a/docs/tools/qemu-img.rst b/docs/tools/qemu-img.rst
> > index b615aa8419..5cc585dc27 100644
> > --- a/docs/tools/qemu-img.rst
> > +++ b/docs/tools/qemu-img.rst
> > @@ -866,6 +866,18 @@ Supported image file formats:
> >       issue ``lsattr filename`` to check if the NOCOW flag is set or not
> >       (Capital 'C' is NOCOW flag).
> > +  ``data_file``
> > +    Pathname that refers to a file that will store all guest data. If
> > +    this option is used, the qcow2 file will only contain the image's
> > +    metadata.
>
> I think I would like a note here about the fact that when passing this 
> option to qemu-img create, the given data file will be newly created, 
> i.e. if it already contains data, all that data will be lost.  And 
> perhaps also note that qemu-img amend on the other hand will only change 
> the reference in the qcow2 file, so the given file should already exist 
> and will not be overwritten.
>
> (“Pathname that refers to a file” sounds like the file may already exist 
> before this operation, which may give people ideas.  (Not that the ideas 
> were bad, it’s just that they have to take care.  Referencing qemu-img 
> amend should give them a hint on how to do it right.))

Hey, I just wanted to leave a note indicating that I'm not ignoring this 
review; I've incorporated it in my next version but I am waiting until 
after the freeze to send it.

Thank you!

Connor