All of lore.kernel.org
 help / color / mirror / Atom feed
From: Brad Campbell <lists2009@fnarfbargle.com>
To: Kevin Wolf <kwolf@redhat.com>
Cc: Stefan Hajnoczi <stefanha@gmail.com>, qemu-devel@nongnu.org
Subject: Re: [Qemu-devel] Qemu-img convert with -B
Date: Wed, 27 Apr 2011 22:02:22 +0800	[thread overview]
Message-ID: <4DB821EE.8010706@fnarfbargle.com> (raw)
In-Reply-To: <4DB8209A.7070400@redhat.com>

On 27/04/11 21:56, Kevin Wolf wrote:

> When you don't have a backing file, leaving an cluster unallocated means
> that it's zero. When you have a backing file, it could be anything. So
> if qemu-img convert wanted to save this space, it would have to read
> from the backing file and leave the cluster unallocated if it reads as zero.
>
> This is something that qemu-img doesn't do today.

... which would explain the behaviour I'm seeing then. Great, time to 
dust off my Kernighan & Ritchie I guess.

Thanks for the explanation.

Regards,
Brad

  reply	other threads:[~2011-04-27 14:02 UTC|newest]

Thread overview: 10+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2011-04-27  3:05 [Qemu-devel] Qemu-img convert with -B Brad Campbell
2011-04-27  8:10 ` Stefan Hajnoczi
2011-04-27  8:56   ` Brad Campbell
2011-04-27 10:06     ` Kevin Wolf
2011-04-27 13:45       ` Brad Campbell
2011-04-27 13:56         ` Kevin Wolf
2011-04-27 14:02           ` Brad Campbell [this message]
2011-04-28  2:06             ` Brad Campbell
2011-04-28  6:36               ` Kevin Wolf
2011-04-28  9:38                 ` Brad Campbell

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=4DB821EE.8010706@fnarfbargle.com \
    --to=lists2009@fnarfbargle.com \
    --cc=kwolf@redhat.com \
    --cc=qemu-devel@nongnu.org \
    --cc=stefanha@gmail.com \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body.
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.