From mboxrd@z Thu Jan 1 00:00:00 1970 From: Anthony Liguori Subject: Re: [Xen-tools] Re: [PATCH] Make xend reject duplicates and rename zombies Date: Fri, 16 Sep 2005 16:49:58 -0500 Message-ID: <432B3E06.4090108@us.ibm.com> References: <87br2uz5yj.fsf@us.ibm.com> <4329C366.2070006@us.ibm.com> <3d8eece205091612523cf7b900@mail.gmail.com> <432B3B13.4070705@us.ibm.com> <3d8eece2050916144823f8c859@mail.gmail.com> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <3d8eece2050916144823f8c859@mail.gmail.com> List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Sender: xen-devel-bounces@lists.xensource.com Errors-To: xen-devel-bounces@lists.xensource.com To: Christian.Limpach@cl.cam.ac.uk Cc: Xen Tools Developers , Dan Smith , Xen Developers List-Id: xen-devel@lists.xenproject.org Christian Limpach wrote: >On 9/16/05, Anthony Liguori wrote: > > >>>I think renaming would make sense if a domain is crashed. You might >>>want to keep the domain around to attach a debugger to it but at the >>>same time restart a fresh copy as soon as possible. >>> >>> >>As long as you can make sure to rename *after* all of the devices have >>been properly torn down. >> >>Otherwise, we need to make sure to make it well known that restarting a >>domain after a crash can result in very bad things :-) >> >> > >How so? The crashed domain is certainly not going to do anything with >those devices anymore... Actually, I'm not even sure I buy the >"unsafe to reuse devices" argument if the domain is only hanging >around in an almost dead state -- it's almost dead, it's not going to >do any requests on those devices anymore... > > I'm thinking specifically about block devices. While the domain may have died, there may be requests in the block devices queues that have not been flushed to disk yet. This is what would lead to problems.. Regards, Anthony Liguori >So regarding the check for termination in check_name, if we only >switch the state to terminated once the domain is almost dead, reusing >the name should be fine... > > christian > > >