Re: [Qemu-devel] [PATCH] qemu-img: document qed format on qemu-img man page

[Stefan Hajnoczi <stefanha@linux.vnet.ibm.com>]

On Tue, Jun 12, 2012 at 05:15:29PM +0200, Kevin Wolf wrote:
> Am 12.06.2012 17:05, schrieb Stefan Hajnoczi:
> > The qemu-img.1 man page is missing the qed format from its list of
> > supported formats.  Document the image creation options for qed.
> > 
> > Suggested-by: Michael Tokarev <mjt@tls.msk.ru>
> > Signed-off-by: Stefan Hajnoczi <stefanha@linux.vnet.ibm.com>
> > ---
> > When the qcow2 QED mode is merged we can update this again to reflect good
> > cache=writethrough performance in qcow2v3 /w QED mode.
> > 
> >  qemu-img.texi |   22 ++++++++++++++++++++++
> >  1 file changed, 22 insertions(+)
> > 
> > diff --git a/qemu-img.texi b/qemu-img.texi
> > index 6fc3c28..78640a9 100644
> > --- a/qemu-img.texi
> > +++ b/qemu-img.texi
> > @@ -232,6 +232,28 @@ to grow.
> >  
> >  @end table
> >  
> > +@item qed
> > +Image format with support for backing files and compact image files (when your
> > +filesystem or transport medium does not support holes).  Good performance due
> > +to less metadata than the more featureful qcow2 format, especially with
> > +cache=writethrough.
> 
> Can we restrict this clearly to cache=writethrough only and possibly add
> a few words about QED's future?
> 
> It's good to have the option today for the few people that actually need
> cache=writethrough, but I don't want more people than necessary to use
> it only to notice after a while that there's no more active development
> of QED and they have to do a painful conversion of all their images.

Yes, that makes sense.  Will send a v2.

Stefan