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

[Kevin Wolf <kwolf@redhat.com>]

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.

Kevin