From mboxrd@z Thu Jan  1 00:00:00 1970
Received: from mailman by lists.gnu.org with tmda-scanned (Exim 4.43)
	id 1HNpT8-0007s8-Lf
	for qemu-devel@nongnu.org; Sun, 04 Mar 2007 07:05:38 -0500
Received: from exim by lists.gnu.org with spam-scanned (Exim 4.43)
	id 1HNpT6-0007rw-Bd
	for qemu-devel@nongnu.org; Sun, 04 Mar 2007 07:05:37 -0500
Received: from [199.232.76.173] (helo=monty-python.gnu.org)
	by lists.gnu.org with esmtp (Exim 4.43) id 1HNpT6-0007rt-6a
	for qemu-devel@nongnu.org; Sun, 04 Mar 2007 07:05:36 -0500
Received: from mail.codesourcery.com ([65.74.133.4])
	by monty-python.gnu.org with esmtps
	(TLS-1.0:DHE_RSA_AES_256_CBC_SHA:32) (Exim 4.52) id 1HNpT5-0002KJ-5F
	for qemu-devel@nongnu.org; Sun, 04 Mar 2007 07:05:35 -0500
From: Paul Brook <paul@codesourcery.com>
Subject: Re: [Qemu-devel] QEMU/pc and scsi disks
Date: Sun, 4 Mar 2007 12:05:28 +0000
References: <45E70CCF.40800@bull.net>
	<200703041144.00936.paul@codesourcery.com>
	<45EAB217.8080708@qumranet.com>
In-Reply-To: <45EAB217.8080708@qumranet.com>
MIME-Version: 1.0
Content-Type: text/plain;
  charset="iso-8859-1"
Content-Transfer-Encoding: 7bit
Content-Disposition: inline
Message-Id: <200703041205.29153.paul@codesourcery.com>
Reply-To: qemu-devel@nongnu.org
List-Id: qemu-devel.nongnu.org
List-Unsubscribe: <http://lists.nongnu.org/mailman/listinfo/qemu-devel>,
	<mailto:qemu-devel-request@nongnu.org?subject=unsubscribe>
List-Archive: <http://lists.gnu.org/pipermail/qemu-devel>
List-Post: <mailto:qemu-devel@nongnu.org>
List-Help: <mailto:qemu-devel-request@nongnu.org?subject=help>
List-Subscribe: <http://lists.nongnu.org/mailman/listinfo/qemu-devel>,
	<mailto:qemu-devel-request@nongnu.org?subject=subscribe>
To: qemu-devel@nongnu.org

On Sunday 04 March 2007 11:48, Avi Kivity wrote:
> Paul Brook wrote:
> >> Out of curiosity, why?  If the options are store in some database, as is
> >> likely, surely it is easier to generate a longish command line than to
> >> generate a unique name for a file, remove it if it already exists, write
> >> out the data, launch qemu, and clean up the file later?  And for
> >> migration, you have to regenerate it, since some options may have
> >> changed (cdrom media).
> >
> > You're going to start hitting commandline length limits fairly rapidly
> > (Windows in particular has a fairly low limit).
>
> Well, at list on linux, the limit is sane (1024 or 10240?).

IIRC linux has a ~32k commandline limit. I wouldn't be surprised if configs 
end up exceeding that.  If you're running on linux then creating a temporary 
file is also trivial[1].

Paul

[1] see mkstemp(3) and tmpfile(3).