From mboxrd@z Thu Jan 1 00:00:00 1970 From: "Serge E. Hallyn" Subject: Re: [BUG][cryo] Create file on restart ? Date: Wed, 16 Jul 2008 21:18:34 -0500 Message-ID: <20080717021834.GA21726@us.ibm.com> References: <20080716185027.GA1335@us.ibm.com> <20080716192604.GA27454@us.ibm.com> <20080716204529.GA4278@us.ibm.com> <20080716205737.GA2082@us.ibm.com> <20080716212609.GB4278@us.ibm.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: Content-Disposition: inline In-Reply-To: <20080716212609.GB4278-r/Jw6+rmf7HQT0dZR+AlfA@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: sukadev-r/Jw6+rmf7HQT0dZR+AlfA@public.gmane.org Cc: Containers List-Id: containers.vger.kernel.org Quoting sukadev-r/Jw6+rmf7HQT0dZR+AlfA@public.gmane.org (sukadev-r/Jw6+rmf7HQT0dZR+AlfA@public.gmane.org): > Serge E. Hallyn [serue-r/Jw6+rmf7HQT0dZR+AlfA@public.gmane.org] wrote: > | Quoting sukadev-r/Jw6+rmf7HQT0dZR+AlfA@public.gmane.org (sukadev-r/Jw6+rmf7HQT0dZR+AlfA@public.gmane.org): > | > Serge E. Hallyn [serue-r/Jw6+rmf7HQT0dZR+AlfA@public.gmane.org] wrote: > | > | Quoting sukadev-r/Jw6+rmf7HQT0dZR+AlfA@public.gmane.org (sukadev-r/Jw6+rmf7HQT0dZR+AlfA@public.gmane.org): > | > | > > | > | > cryo does not (cannot ?) recreate files if the application created > | > | > | > | I think that's for the best. > | > | > | > | Don't you? > | > > | > I can understand that configuration or data files should exist, but > | > not sure about temporary or log files that an application created > | > upon start-up and expects to be present. Should the admin find > | > out about them and create them by hand before restart ? > | > | I think the admin should have set the destination environment such that > | the task is restarted in the same network fs in the same directory, with > | no files having been deleted. > > or new files created ? For instance if the application was checkpointed > before it created a temporary file with O_EXCL flag, that temporary > file must not exist when restarting ? > > | > | Am I wrong? > > So we take a snapshot of the FS and checkpoint the application. Do they > need to be atomic ? > > Eitherway, I withdraw the bug :-) Well it's certainly beyond the scope of cryo. I'd prefer if we didn't have to snapshot the fs at each checkpoint (!) and I think any many or most cases (think one long-running scientific app or seti@home that just occasionally gets migrated or stopped for a reboot) it won't be an issue. But your point seems valid. -serge