From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1750961AbXD0Vjq (ORCPT ); Fri, 27 Apr 2007 17:39:46 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1757349AbXD0Vjq (ORCPT ); Fri, 27 Apr 2007 17:39:46 -0400 Received: from nigel.suspend2.net ([203.171.70.205]:39721 "EHLO nigel.suspend2.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750961AbXD0Vjp (ORCPT ); Fri, 27 Apr 2007 17:39:45 -0400 Subject: Re: Back to the future. From: Nigel Cunningham Reply-To: nigel@nigel.suspend2.net To: Pavel Machek Cc: Pekka Enberg , Linus Torvalds , LKML In-Reply-To: <20070427145507.GP22250@elf.ucw.cz> References: <1177567481.5025.211.camel@nigel.suspend2.net> <84144f020704260028q190fc90fs8f9ea703e42e7910@mail.gmail.com> <1177573348.5025.224.camel@nigel.suspend2.net> <20070426224005.GA21926@elf.ucw.cz> <84144f020704262241s5bcfc043k55f9d60e368b3c9e@mail.gmail.com> <20070427145507.GP22250@elf.ucw.cz> Content-Type: multipart/signed; micalg=pgp-sha1; protocol="application/pgp-signature"; boundary="=-Zch4jxUWvr1/A4KzRaRy" Date: Sat, 28 Apr 2007 07:39:45 +1000 Message-Id: <1177709985.4737.166.camel@nigel.suspend2.net> Mime-Version: 1.0 X-Mailer: Evolution 2.10.1 Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org --=-Zch4jxUWvr1/A4KzRaRy Content-Type: text/plain Content-Transfer-Encoding: quoted-printable Hi. On Fri, 2007-04-27 at 16:55 +0200, Pavel Machek wrote: > On Fri 2007-04-27 08:41:56, Pekka Enberg wrote: > > On 4/27/07, Pavel Machek wrote: > > >Now, it would be _very_ nice to be able to snapshot system and > > >continue running, but I just don't see how to do it without extensive > > >filesystem support. > >=20 > > So what kind of support do we need from the filesystem? >=20 > "forcedremount ro, not telling anyone, not killing processes" would do > the trick. FS snapshots might do. It sounds to me more like Pekka is thinking of checkpointing support. If that's the case, then remounting filesystems isn't going to be an option. You want to freeze them for just long enough so that you can determine what needs saving in the checkpoint. You certainly don't want to make rw file handles ro and so on. Nigel --=-Zch4jxUWvr1/A4KzRaRy Content-Type: application/pgp-signature; name=signature.asc Content-Description: This is a digitally signed message part -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.6 (GNU/Linux) iD8DBQBGMm2hN0y+n1M3mo0RAmdHAJwI+v0TBymaXWkrBQ0CEV1VBNX4awCg6xEa w0Tmcy6Momy8gd5DwVsFhVo= =Gw2u -----END PGP SIGNATURE----- --=-Zch4jxUWvr1/A4KzRaRy--