From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mailman by lists.gnu.org with tmda-scanned (Exim 4.43) id 1ExpLe-0001C0-4M for qemu-devel@nongnu.org; Sat, 14 Jan 2006 12:37:54 -0500 Received: from exim by lists.gnu.org with spam-scanned (Exim 4.43) id 1ExpLb-0001BS-Ew for qemu-devel@nongnu.org; Sat, 14 Jan 2006 12:37:53 -0500 Received: from [199.232.76.173] (helo=monty-python.gnu.org) by lists.gnu.org with esmtp (Exim 4.43) id 1ExpLb-0001BM-2r for qemu-devel@nongnu.org; Sat, 14 Jan 2006 12:37:51 -0500 Received: from [64.233.184.196] (helo=wproxy.gmail.com) by monty-python.gnu.org with esmtp (Exim 4.34) id 1ExpOm-0002Kd-7h for qemu-devel@nongnu.org; Sat, 14 Jan 2006 12:41:08 -0500 Received: by wproxy.gmail.com with SMTP id 57so840483wri for ; Sat, 14 Jan 2006 09:35:29 -0800 (PST) Message-ID: Date: Sat, 14 Jan 2006 18:35:29 +0100 From: Thomas Steffen Subject: Re: [Qemu-devel] Qemu - where will it go? In-Reply-To: <200601141132.03700.info@j-pfennig.de> MIME-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: quoted-printable Content-Disposition: inline References: <200601141132.03700.info@j-pfennig.de> Reply-To: qemu-devel@nongnu.org List-Id: qemu-devel.nongnu.org List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: qemu-devel@nongnu.org Hi Juergen! On 1/14/06, Juergen Pfennig wrote: > as I found out qemu is quite stable and has acceptable performance. Using= it you > could freeze legacy applications using a legacy OS like win 2003 or win X= P. I am > talking of periods from 5 to 20 years! Yes, that is a good idea. Having a defined VM is probably the most stable computing environment you can get. If it is a well used one, all the better. I have seen research projects that would build a custom VM in Java (!), and then program a PDF viewer for this VM. Which is of course mostly useless, compared to all the great things you can do with Qemu, and without Java. > But a lot of work would have to be done. The next steps of development wo= uld > probably include: > > - run qemu as a service (on Windows or on Linux using xinetd) > - make rdp (Win Terminal Server) work when qemu started via > xinetd > - improve disk image format, better snapshot handling > - make a plugin architecture for the host side device implementation > - allow 'remote' host side devices (sound, usb, serial ...) > - define a protocol to use qemu over a network (should multiplex > video, sound, usb, serial and so on). While I agree that all these ideas are nice, I am not sure they are essential for a "legacy" VM. I think there are two main considerations: 1. Reduce your dependencies to things that you expect to be around in 10 years time. 2. Keep the data format stable. For 1. it would be nice to use only standard C (POSIX ???), but due to the way Qemu works, it needs to know about the link format used on your platform. ELF seems to be a reasonable stable format, but we have seen several transitions on Linux (glibc4, 5 and now 6), so there could be more (incompatible) changes in the future. 2. is a question of development priorities. Assuming that Qemu 0.8 might not compile in 10 years time any more, Qemu 4.9 (or whatever we have then) should be able to read Qemu 0.8 images. Maybe this is what you mean by "improve disk image format". But since Qemu does supports plain images, I do not see how you could make the format more stable :-) > So you see: in a commercial and or industrial application one would like= to run > the qemus on a server. At least the MS remote desktop protocol should wor= k > well. A qemu specific client would be nicer. Actually X11 should work nicely, and it is much more open than RDP. VNC also seems to be stable, but it is a lot less used. > Unfortunately implementing the things that I was talking about would blow > up the size of the code base dramatically. Qemu would never again be > small, pretty and easy to understand. Where do you want to go? I am not a developer, but I would prefer it small and pretty :-). If it is not fast enough, wait 6 month and buy a faster CPU... But that is just my personal view. Thomas