From mboxrd@z Thu Jan 1 00:00:00 1970 Message-ID: <8ccc8ba40805250848x16f054b8y71b46ff1c346eda4@mail.gmail.com> Date: Sun, 25 May 2008 17:48:15 +0200 From: "Francisco J Ballesteros" To: "Fans of the OS Plan 9 from Bell Labs" <9fans@9fans.net> In-Reply-To: MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit Content-Disposition: inline References: <20080525075632.GA30260@nibiru.local> Subject: Re: [9fans] Fossil+Venti on Linux Topicbox-Message-UUID: ac6ae112-ead3-11e9-9d60-3106f5b1d025 > I believe the Plan B folks did some work with fail-over (amongst other > things) that might be applicable. Beyond that, if you want to get what you You could adapt Plan B's bns to fail over between different FSs. But... We learned that although you can let he FS fail over nicely, many other things stand in the way making it unnecessary to fail over. For example, on Plan 9, cs and dns have problems after a fail over, your IP address may change, etc. All that is to say that when you experience tolerance to FS failures, you still face other things that do not fail over. To tolerate failures what we do is to run venti on a raid. If fossil gets corrupted somehow we'd just format the partition using the last vac. To survive crashes of the machine with the venti we copy its arenas to another machine, aso keeping a raid. If you want clients to stay up during server crashes you could use either bns or recover to pretend the FS is still there (blocked, but there) while you reboot (or replace) it. hth