Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755768AbZC3PBp (ORCPT ); Mon, 30 Mar 2009 11:01:45 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751555AbZC3PBg (ORCPT ); Mon, 30 Mar 2009 11:01:36 -0400 Received: from srv5.dvmed.net ([207.36.208.214]:53849 "EHLO mail.dvmed.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750913AbZC3PBg (ORCPT ); Mon, 30 Mar 2009 11:01:36 -0400 Message-ID: <49D0DE9A.309@garzik.org> Date: Mon, 30 Mar 2009 11:00:42 -0400 From: Jeff Garzik User-Agent: Thunderbird 2.0.0.21 (X11/20090320) MIME-Version: 1.0 To: Mark Lord CC: Ric Wheeler , "Andreas T.Auer" , Alan Cox , Theodore Tso , Stefan Richter , Linus Torvalds , Matthew Garrett , Andrew Morton , David Rees , Jesper Krogh , Linux Kernel Mailing List Subject: Re: Linux 2.6.29 References: <49CD7B10.7010601@garzik.org> <49CD891A.7030103@rtr.ca> <49CD9047.4060500@garzik.org> <49CE2633.2000903@s5r6.in-berlin.de> <49CE3186.8090903@garzik.org> <49CE35AE.1080702@s5r6.in-berlin.de> <49CE3F74.6090103@rtr.ca> <20090329231451.GR26138@disturbed> <20090330003948.GA13356@mit.edu> <49D0710A.1030805@ursus.ath.cx> <20090330100546.51907bd2@the-village.bc.nu> <49D0A3D6.4000300@ursus.ath.cx> <49D0AA4A.6020308@redhat.com> <49D0CDBA.7040702@rtr.ca> <49D0D08E.3090100@redhat.com> <49D0DAD3.6030507@rtr.ca> In-Reply-To: <49D0DAD3.6030507@rtr.ca> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit X-Spam-Score: -4.4 (----) X-Spam-Report: SpamAssassin version 3.2.5 on srv5.dvmed.net summary: Content analysis details: (-4.4 points, 5.0 required) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1587 Lines: 45 Mark Lord wrote: > Ric Wheeler wrote: >> Mark Lord wrote: >>> Ric Wheeler wrote: > .. >>> The kernel can crash, and the drives, in practice, will still >>> flush their caches to media by themselves. Within a second or two. >> >> Even with desktops, I am not positive that the drive write cache >> survives a kernel crash without data loss. If I remember correctly, >> Chris's tests used crashes (not power outages) to display the data >> corruption that happened without barriers being enabled properly. > .. > > Linux f/s barriers != drive write caches. > > Drive write caches are an almost total non-issue for desktop users, > except on the (very rare) event of a total, sudden power failure > during extended write outs. > > Very rare. Heck, even I have lost power on a plane, while a laptop in laptop mode was flushing out work. Not that rare. > Yes, a huge problem for server farms. No question. > But the majority of Linux systems are probably (still) desktops/notebooks. But it doesn't really matter who is what majority, does it? At the present time at least, we have not designated any filesystems "desktop only", nor have we declared Linux a desktop-only OS. Any generalized decision that hurts servers to help desktops would be short-sighted. Robbing Peter, to pay Paul, is no formula for OS success. Jeff -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/