From mboxrd@z Thu Jan 1 00:00:00 1970 From: "Serge E. Hallyn" Subject: Re: C/R: File substitution at restart Date: Wed, 8 Sep 2010 08:09:31 -0500 Message-ID: <20100908130931.GA11161@hallyn.com> References: <4C875F6E.2030004@kerlabs.com> Mime-Version: 1.0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable Return-path: Content-Disposition: inline In-Reply-To: <4C875F6E.2030004-aw0BnHfMbSpBDgjK7y7TUQ@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: Matthieu =?iso-8859-1?Q?Fertr=E9?= Cc: "Serge E. Hallyn" , containers-cunTk1MwBs9QetFLy7KEm3xJsTq8ys+cHZ5vskTnxNA@public.gmane.org, Nathan Lynch , Louis Rilling , Dan Smith , Sukadev Bhattiprolu List-Id: containers.vger.kernel.org Quoting Matthieu Fertr=E9 (matthieu.fertre-aw0BnHfMbSpBDgjK7y7TUQ@public.gmane.org): > Hi, > = > Here is a proposal for a C/R related feature already developed in > Kerrighed: file substitution at restart. > = > The goal of this mail is to start a discussion about adding such feature > to Linux cr. Comments are welcome! Yup, AFAIK metacluster and zap do this too. I don't think there is any question about whether we want to support this, but rather what the user-kernel API should look like. Perhaps the easiest "API" is to have the userspace program rewrite the checkpoint image, but that probably isn't quite as simple as just substituting #s in the image, bc we'll have to also find the place where the source of the original fd was specified and tweak that. I assume this is one of the things Oren would have 'cradvise()' do, and at this point that sounds nice to me - might be worth seeing how the community reacts. Sentiments on such things change, after all. Have there been any other suggestions? -serge