From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:42954) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1frZbJ-0002ug-Gv for qemu-devel@nongnu.org; Sun, 19 Aug 2018 22:07:26 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1frZbI-0006S4-UR for qemu-devel@nongnu.org; Sun, 19 Aug 2018 22:07:25 -0400 Date: Mon, 20 Aug 2018 10:07:15 +0800 From: Fam Zheng Message-ID: <20180820020715.GB10682@lemon.usersys.redhat.com> References: <20180815025614.53588-1-eblake@redhat.com> <20180815025614.53588-3-eblake@redhat.com> <48010463-405e-bb08-f9c5-8263dcf3bb48@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <48010463-405e-bb08-f9c5-8263dcf3bb48@redhat.com> Subject: Re: [Qemu-devel] [PATCH 2/2] qemu-img: Add dd seek= option List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Max Reitz Cc: Eric Blake , qemu-devel@nongnu.org, Kevin Wolf , fullmanet@gmail.com, qemu-block@nongnu.org On Thu, 08/16 04:20, Max Reitz wrote: > No, the real issue is that dd is still not implemented just as a > frontend to convert. Which it should be. I'm not sure dd was a very > good idea from the start, and now it should ideally be a frontend to > convert. > > (My full opinion on the matter: dd has a horrible interface. I don't > quite see why we replicated that inside qemu-img. Also, if you want to > use dd, why not use qemu-nbd + Linux nbd device + real dd?) The intention is that dd is a familiar interface and allows for operating on portions of images. It is much more convenient than "qemu-nbd + Linux nbd + dd" and a bit more convenient than "booting a Linux VM, attaching the image as a virtual disk, then use dd in the guest". More so when writing tests. Fam