Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id ; Thu, 12 Jul 2001 14:49:28 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id ; Thu, 12 Jul 2001 14:49:09 -0400 Received: from h131s117a129n47.user.nortelnetworks.com ([47.129.117.131]:26762 "HELO pcard0ks.ca.nortel.com") by vger.kernel.org with SMTP id ; Thu, 12 Jul 2001 14:48:53 -0400 Message-ID: <3B4DF114.44272B74@nortelnetworks.com> Date: Thu, 12 Jul 2001 14:48:52 -0400 From: Chris Friesen X-Mailer: Mozilla 4.77 [en] (X11; U; Linux 2.4.3-custom i686) X-Accept-Language: en MIME-Version: 1.0 To: "Albert D. Cahalan" Cc: linux-kernel@vger.kernel.org Subject: Re: Switching Kernels without Rebooting? In-Reply-To: <200107121623.f6CGNV569053@saturn.cs.uml.edu> Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org "Albert D. Cahalan" wrote: > The 24x7 places might be willing to pay somebody to do this. > It's consulting work really. The customer says "I want to go > from 2.4.8 to 2.4.12", you say "OK, $320405 please.", and you > make a custom upgrade procedure for them. Speaking as someone who is working on what will eventually be a five 9's project based on linux, there is almost zero chance that we would make use of something like this. Applications and kernels are tested together and verified together, and the likelihood of changing either one and not the other one is very low (and in fact they are shipped together as a single image). We have hardware redundancy, and upgrades are controlled by the application, since it knows exactly what state must be transferred and what the differences are between versions. After all the state has been transferred we then do an IP takeover so that the rest of the system knows to talk to the new side. At this point we can test the new side for a while. If we're satisfied with how its performing, we can then take down the inactive side and upgrade it and then bring it back into sync with the active side. If we don't like it, we can always abort and switch back to the old version. -- Chris Friesen | MailStop: 043/33/F10 Nortel Networks | work: (613) 765-0557 3500 Carling Avenue | fax: (613) 765-2986 Nepean, ON K2H 8E9 Canada | email: cfriesen@nortelnetworks.com - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/