From mboxrd@z Thu Jan 1 00:00:00 1970 From: Charles Duffy Subject: Re: Basic xenstore questions (building a watchdog) Date: Fri, 13 Jan 2006 09:16:41 -0600 Message-ID: <43C7C459.1070107@spamcop.net> References: <200601131451.02874.mark.williamson@cl.cam.ac.uk> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <200601131451.02874.mark.williamson@cl.cam.ac.uk> List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Sender: xen-devel-bounces@lists.xensource.com Errors-To: xen-devel-bounces@lists.xensource.com To: Mark Williamson Cc: xen-devel@lists.xensource.com List-Id: xen-devel@lists.xenproject.org Mark Williamson wrote: >> I'm looking at building a xenstore-based watchdog, as described at >> http://lists.xensource.com/archives/html/xen-users/2005-07/msg00597.html >> > > Sounds cool! > > I knocked up a little prototype of one some time last year. The Xend code was > surprisingly tricky (couldn't get rebooting the domain to behave right, > although I didn't try very hard). You'd be welcome to the kernel code if you > want to take a look, although it's very simple - the hacks required to the > softdog device in Linux were minimal. > I would be very much interested in looking at what you've got so far, as an example if not a base. > I'd suggest as an alternative to using the store, you might like to think > about adding watchdog functionality to Xen itself... The advantage here is > that it also allows you to watchdog dom0, without requiring watchdog > hardware. Timing out dom0 would reboot the system, a domU would just result > in its destruction (and the tools recreating it). > It's a thought, yes -- but I'm already outside the realm of stuff-I-know, and I'd like to get at least *something* in working condition before I stray much further. Also, I'm under the impression that running softdog in dom0 with nowayout set should provide similar functionality -- perhaps I saw someone mentioning on the ML that they were doing just that?