From mboxrd@z Thu Jan 1 00:00:00 1970 From: Daniel Lezcano Subject: Re: [PATCH] [RFC] c/r: Add UTS support Date: Thu, 12 Mar 2009 23:48:36 +0100 Message-ID: <49B99144.9000106@free.fr> References: <1236880612-15316-1-git-send-email-danms@us.ibm.com> <20090312162954.4a4b8e00@thinkcentre.lan> <87fxhipfrh.fsf@caffeine.danplanet.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <87fxhipfrh.fsf-FLMGYpZoEPULwtHQx/6qkW3U47Q5hpJU@public.gmane.org> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: containers-bounces-cunTk1MwBs9QetFLy7KEm3xJsTq8ys+cHZ5vskTnxNA@public.gmane.org Errors-To: containers-bounces-cunTk1MwBs9QetFLy7KEm3xJsTq8ys+cHZ5vskTnxNA@public.gmane.org To: Dan Smith Cc: containers-qjLDD68F18O7TbgM5vRIOg@public.gmane.org, Nathan Lynch List-Id: containers.vger.kernel.org Dan Smith wrote: > NL> I'd like there to be some discussion about this, because namespace > NL> creation seems like a significant addition to the semantics of > NL> restart as I understand it. > > Indeed. > > NL> Is namespace creation during restart unavoidable, or merely > NL> desirable? Is there a case for requiring the user to provide a > NL> suitable namespace environment before attempting restart? > > Information about the namespaces has to be saved at checkpoint time no > matter what, right? I guess I don't see any compelling reason to not > have the restart operation replicate the environment of the original > process. Otherwise we require userspace to read and interpret the > checkpoint stream and selectively feed the bits that the kernel is > responsible for to the kernel and process the rest itself (or have the > kernel ignore those records). > Assuming you have a process and this one unshared the network 100 times and each time opens a socket, how do you checkpoint these namespaces ? > What's the argument for depending on userspace to set this up? > Maybe, CR of the namespaces is more complicate topic than it looks like and the CR itself is big enough to not complicate things. IMHO, I would recommend as the first step to forbid the unshare inside a container and let the container implementation to save the configuration with the statefile in order to recreate it at the restart