From owner-freebsd-stable Thu Sep 12 19: 6:22 2002 Delivered-To: freebsd-stable@freebsd.org Received: from mx1.FreeBSD.org (mx1.FreeBSD.org [216.136.204.125]) by hub.freebsd.org (Postfix) with ESMTP id 5493437B400 for ; Thu, 12 Sep 2002 19:06:19 -0700 (PDT) Received: from mail2.dreamscape.com (mail2.dreamscape.com [206.64.128.18]) by mx1.FreeBSD.org (Postfix) with ESMTP id 7ABFF43E65 for ; Thu, 12 Sep 2002 19:06:18 -0700 (PDT) (envelope-from krentel@dreamscape.com) Received: from dreamscape.com (sA13-p10.dreamscape.com [209.4.255.74]) by mail2.dreamscape.com (8.9.3+blt/8.9.3) with ESMTP id WAA14463; Thu, 12 Sep 2002 22:06:07 -0400 (EDT) Received: from blue.mwk.domain (localhost [127.0.0.1]) by dreamscape.com (8.11.1/8.11.1) with ESMTP id g8D24ib70307; Thu, 12 Sep 2002 22:04:45 -0400 (EDT) (envelope-from krentel@blue.mwk.domain) Message-Id: <200209130204.g8D24ib70307@dreamscape.com> To: freebsd-stable@freebsd.org Cc: dillon@backplane.com Subject: Linux dump in 2.4 kernels Date: Thu, 12 Sep 2002 22:04:44 -0400 From: "Mark W. Krentel" Sender: owner-freebsd-stable@FreeBSD.ORG Precedence: bulk List-ID: List-Archive: (Web Archive) List-Help: (List Instructions) List-Subscribe: List-Unsubscribe: X-Loop: FreeBSD.ORG A thousand pardons for bringing up a Linux issue here. I just wanted to correct something I said earlier. A couple months ago, there was a thread on -stable about ext2 dump in the Linux 2.4.x kernels. See "Glacial speed of dump backups" around July 23-25. I claimed that the cache design in the 2.4.x kernels made it impossible for ext2 dump to work correctly on an idle but mounted file system. This is not correct. There were bugs in the early 2.4 kernels that caused the problems I was seeing. But they were bugs, not a design decision that would deprecate dump, and many of them have since been fixed. I misinterpreted some of my conversation with the Linux dump maintainer which led to my erroneous conclusion. I'm not saying that all such bugs have been fixed. I've seen problems as late as RH 7.3 (2.4.18 kernel). I'm just saying that ext2 dump is supposed to be viable on a mounted file system, provided of course, the file system is idle, you sync(), etc. And if it's not, then it's a kernel bug. My advice to people running dump in Linux is to upgrade to both the latest kernel and the most recent dump release. I'd also like to apologize to Matthew Dillon for not believing him. Matthew said (regarding dump), "I do not know of any issues with Linux that make it any different from FreeBSD. If you sync a couple of times dumping an idle filesystem under Linux ought to work just about the same as dumping an idle filesystem under FreeBSD." At the time, I didn't believe him, so I apologize. And please, I don't want to start a big thread on this. dump-users@lists.sourceforge.net would be a great place for further discussion. I just wanted to correct one piece of FUD I may have said. --Mark To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-stable" in the body of the message