Re: [Qemu-devel] [PATCH 2/5] blockdev: add discard suboption to -drive

[Stefan Hajnoczi]

On Wed, Feb 20, 2013 at 03:09:51PM +0100, Paolo Bonzini wrote:
> Il 13/02/2013 11:39, Stefan Hajnoczi ha scritto:
> >> >              .type = QEMU_OPT_STRING,
> >> >              .help = "disk image",
> >> >          },{
> >> > +            .name = "discard",
> >> > +            .type = QEMU_OPT_STRING,
> >> > +            .help = "discard operation (ignore/off, unmap/on)",
> > off/on aliases will be confusing when we plan to add "anchor" in the
> > future, making this non-boolean.  Please support ignore/unmap only.
> 
> My problem here is that "unmap" will not be the default but at the same
> time it will be what people want to use.  Hence, it is important to have
> an easy to remember and discover option; "discard=on" is immediately
> understandable, while "discard=unmap" is not.

I understand.  The risk is that we end up confusing users rather than
helping, because the actual ignore/anchor/unmap modes need to be
understood to use this feature properly.

If you and Kevin like the off/on alias, go ahead.  It's not critical.

Stefan