From owner-freebsd-isp Thu Jan 20 4:34:58 2000 Delivered-To: freebsd-isp@freebsd.org Received: from doriath.saers.com (libretto.x0.net [193.216.248.37]) by hub.freebsd.org (Postfix) with ESMTP id 29B3015409 for ; Thu, 20 Jan 2000 04:34:55 -0800 (PST) (envelope-from niklasmls@saers.com) Received: from localhost (niklasmls@localhost) by doriath.saers.com (8.9.3/8.9.3) with ESMTP id NAA99664 for ; Thu, 20 Jan 2000 13:34:54 +0100 (CET) (envelope-from niklasmls@saers.com) Date: Thu, 20 Jan 2000 13:34:53 +0100 (CET) From: Niklas Saers Mailinglistaccount To: freebsd-isp@freebsd.org Subject: mirroring-solutions Message-ID: MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: owner-freebsd-isp@FreeBSD.ORG Precedence: bulk X-Loop: FreeBSD.org Hi, I'd like to ask you for some input on a mirroring-topic: Right now I'm running the box doriath.saers.com. It's having accounts for about a hundered users, has about 50 web-virtualhosts (running Apache&PHP), runs a couple of databases under MySQL and it runs DNS for a couple of domains. That's pretty much all the box does. As I'm no large, commercial business but only a student, all this has been packed into one box. But, a recent downtime because of a disk failure has alerted me. Problem is, I'm going to be on the other side of the planet as an exchange student for an entire year. During that time I need the computer to be up. My users need the computer to be up. As you all know, disks do crash, shit does happen. So I'd like to be prepared for this. My idea is to set up a twin-box which mirrors the entire computer. When doriath goes down, this mirror-box will replace it. Sounds good, but I'm not sure about how to solve this practically. What would be nice to is that if I first have another mirror-box up, this could be used for load balancing. So, my idea is as following: set up two extra boxes: one mirror of doriath and one load-balancing server. This sounds nice, but I have a few questions even to this: - How do I ensure that changes which happen on box a are updated on box b as well? - How do I ensure that changes on myfile on box a and changes on myfile on box b look like one change on the box? If programming one box I'd use semaphores or transactions (depending on what I was writing) but how do I see to it that this goes smooth so that no data is being outdated or invalid? - What software should I use for load-balancing? - Can I use this software for all the services described above? And most of all: what happens if the load-balancing server crashes? Will both the mirror boxes be unavailable? Because if this happens, we're back to scratch. Will it be better for uptime that I have one mirror-computer up and just change the IP on the box when the other one goes down? Thanks in advance for your thoughts on this matter :) Niklas Saers To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-isp" in the body of the message