Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S261677AbVEOQuq (ORCPT ); Sun, 15 May 2005 12:50:46 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S261680AbVEOQuq (ORCPT ); Sun, 15 May 2005 12:50:46 -0400 Received: from smtpout.mac.com ([17.250.248.73]:26614 "EHLO smtpout.mac.com") by vger.kernel.org with ESMTP id S261677AbVEOQum (ORCPT ); Sun, 15 May 2005 12:50:42 -0400 In-Reply-To: <42877C1B.2030008@pobox.com> References: <200505151121.36243.gene.heskett@verizon.net> <20050515152956.GA25143@havoc.gtf.org> <20050516.012740.93615022.okuyamak@dd.iij4u.or.jp> <42877C1B.2030008@pobox.com> Mime-Version: 1.0 (Apple Message framework v728) Content-Type: text/plain; charset=US-ASCII; delsp=yes; format=flowed Message-Id: <37C1BFCF-1B30-4781-AC72-81513650AD50@mac.com> Cc: Kenichi Okuyama , gene.heskett@verizon.net, linux-kernel@vger.kernel.org Content-Transfer-Encoding: 7bit From: Kyle Moffett Subject: Re: Disk write cache Date: Sun, 15 May 2005 12:50:22 -0400 To: Jeff Garzik X-Mailer: Apple Mail (2.728) Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 730 Lines: 17 On May 15, 2005, at 12:43:07, Jeff Garzik wrote: > The only way to you can be assured that your data has "hit the > platter" is > (1) issuing [FLUSH|SYNC] CACHE, or > (2) using FUA-style disk commands And even then, some battery-backed RAID controllers will completely ignore cache-flushes, because in the event of a power failure they can maintain the cached data for anywhere from a couple days to a month or two, depending on the quality of the card and the size of its battery. - 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/