From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from sc8-sf-mx1-b.sourceforge.net ([10.3.1.11] helo=sc8-sf-mx1.sourceforge.net) by sc8-sf-list1.sourceforge.net with esmtp (Exim 4.30) id 1CxRAT-00078r-Q6 for user-mode-linux-devel@lists.sourceforge.net; Sat, 05 Feb 2005 06:44:13 -0800 Received: from mail-in-09.arcor-online.net ([151.189.21.49]) by sc8-sf-mx1.sourceforge.net with esmtp (TLSv1:AES256-SHA:256) (Exim 4.41) id 1CxRAT-0007b0-2c for user-mode-linux-devel@lists.sourceforge.net; Sat, 05 Feb 2005 06:44:13 -0800 Message-ID: <4204DC49.1070102@upb.de> From: =?ISO-8859-15?Q?Sven_K=F6hler?= MIME-Version: 1.0 Subject: Re: Sky, comma, falling. (Was Re: [uml-devel] Xen going to be in Kernel 2.6 soon?) References: <200502042113.13876.rob@landley.net> In-Reply-To: <200502042113.13876.rob@landley.net> Content-Type: text/plain; charset=ISO-8859-15; format=flowed Content-Transfer-Encoding: 7bit Sender: user-mode-linux-devel-admin@lists.sourceforge.net Errors-To: user-mode-linux-devel-admin@lists.sourceforge.net List-Unsubscribe: , List-Id: The user-mode Linux development list List-Post: List-Help: List-Subscribe: , List-Archive: Date: Sat, 05 Feb 2005 15:46:33 +0100 To: Rob Landley Cc: user-mode-linux-devel@lists.sourceforge.net >> I feel like this is a slap in Jeff's face, since i thought >>that UML will be developed as the first choice in virtualizations >>techniques. > > Yup, just like the inclusion of reiserfs in the kernel is a slap in the face > to ext3. Obviously they did it just to be insulting, didn't you read Linus's > "I'm a bastard" speech? No, i don't know that speech. In addition i like reiserfs, so i'm perhaps the wrong person to discuss that with. The next thing on the horizon is reiser4 - perhaps with the "files as directory" feature - what ever that means, but i guess i won't like it. >>So what is it all about? When should somebody chose Xen, and when should >>somebody chose UML? and how will UML and Xen compete? > > You know, ever since the release of the BSD source code in 1992 totally > derailed that "Linux" project people were playing with back then, this kind > of question has become vitally important. The release of any remotely > similar project obviously can immediately halt all development of established > projects that developers have sunk years of effort into, and they immediately > start porting over things like the COW mounts and hostfs and honeypot procfs, > and rewrite all the existing tutorials and retrain everybody overnight to > work on the new as yet untested thingy that hasn't been particularly debugged > yet. So you critisize, that they don't concentrate forces on UML? I Agree. With the integration of UML into the Linux-Kernel i thought, that it would speed up development of UML and make it more stable. Intead, the people still break the UML-stuff regularly and Jeff and Blaisorblade must provide patches again :-( > Especially in a case like this, where Xen actually competes with VMWare rather > than UML. Obviously, UML is doomed. What with Xen requiring a modified host > kernel to provide its virtualization environment whereas UML uses the process > abstraction to virtualize it: I mean, who's going to use _processes_ in five > years, will future kernels even bother to support them? Sure, UML not only > runs on an unmodified Linux kernel (even running a 2.6 UML on a 2.2 host > kernel), and even an effort underway to get it running on windows (who knows > why, but a MacOS X host can only be a matter of time), but that just means > maybe it can scrape on some tiny niches once it's driven off Linux by this > new "Adeos" thing... Er, I mean "Plex86"... Um... "Xen", that's it. And > obviously its original use as a Linux development tool letting you do things > like create a filesystem driver and mount an instance of it without > destablizing your host kernel, or run bits of the kernel under normal > userspace debugging tools... Well, we're well rid of that, aren't we? And > being to swap kernel memory to backing store just like a regular application, > that was obviously a bad idea from day one... VMWare, Xen and UML are different techniques. As far as i know, UML doesn't use processes as the virtualization environment when running in SKAS mode. It runs a new kernel within a different address space - afaik, this is more like VMWare and Xen. But due to haveing a relatively normal hostsystem, there are the advantages you mentioned. You also forgot some things: Xen doesn't support NPTL too > Why was the question interesting again? What's the future of Xen and UML? Will Xen grow bigger than UML? Which is Linus's favourite? UML or Xen? ------------------------------------------------------- This SF.Net email is sponsored by: IntelliVIEW -- Interactive Reporting Tool for open source databases. Create drag-&-drop reports. Save time by over 75%! Publish reports on the web. Export to DOC, XLS, RTF, etc. Download a FREE copy at http://www.intelliview.com/go/osdn_nl _______________________________________________ User-mode-linux-devel mailing list User-mode-linux-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/user-mode-linux-devel