From owner-freebsd-stable Sun Jul 16 19:58: 6 2000 Delivered-To: freebsd-stable@freebsd.org Received: from mail.rpi.edu (mail.rpi.edu [128.113.100.7]) by hub.freebsd.org (Postfix) with ESMTP id 9D80A37B7A7 for ; Sun, 16 Jul 2000 19:58:01 -0700 (PDT) (envelope-from drosih@rpi.edu) Received: from [128.113.24.47] (gilead.acs.rpi.edu [128.113.24.47]) by mail.rpi.edu (8.9.3/8.9.3) with ESMTP id WAA63694; Sun, 16 Jul 2000 22:58:00 -0400 Mime-Version: 1.0 X-Sender: drosih@mail.rpi.edu Message-Id: In-Reply-To: References: Date: Sun, 16 Jul 2000 22:58:58 -0400 To: From: Garance A Drosihn Subject: RE: Upgrading 3.5-STABLE to 4.0-STABLE Cc: Content-Type: text/plain; charset="us-ascii" ; format="flowed" Sender: owner-freebsd-stable@FreeBSD.ORG Precedence: bulk X-Loop: FreeBSD.ORG At 9:40 PM -0400 7/16/00, Phil Rosenthal wrote: >Is it possible to ignore the "reboot in single mode" part? > >It is not possible to get this system into single mode, because >it has to be up, always. >it can have a maximum downtime of maybe 45 seconds, which is >too long to go into single mode and compile stuff. >I know it is obviously more dangerous to be in multi-user mode, >but is it one of those "better safe than sorry, but it will >probably work" things? If you have a machine which really has that kind of uptime requirement, then you need to rethink your upgrade strategy. There's no absolute guarantee that everything is going to work after upgrading (particularly when doing a large jump, such as going from 3.5 to 4.0-stable). Even if everything DOES work, it might be that it'll take an extra 30 seconds to boot up. I can not imagine feeling comfortable saying "sure, go ahead, it will 'probably' work" if you really can not afford a minute's worth of downtime. If the upgrade does work 99% of the time, and you happen to hit that other 1%, then you're screwed. I would not want to be responsible for you finding yourself screwed. I realize you probably also have the constraint that you can not spend any money on redundant equipment, but at some point reality will have to set in. Either get redundant equipment, or give up on 45-second maximum downtime, or simply do not do upgrades. That's just my view of things, of course... In my case, I have a machine where the goal for maximum downtime is more like 30 MINUTES, and yet I have a duplicate machine for that case. I'm certainly not going to recommend that you jump into 4.0-stable on a critical production machine without doing some testing of it before switching to it. [aside: on that machine, I'm about 3 hours away from having one year's worth of continuous uptime... :-) ] --- Garance Alistair Drosehn = gad@eclipse.acs.rpi.edu Senior Systems Programmer or drosih@rpi.edu Rensselaer Polytechnic Institute To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-stable" in the body of the message