From: Steve Brown Subject: Re: ext4 benchmark questions Date: Fri, 23 Apr 2010 10:49:04 -0500 Message-ID: References: <4BD0C50A.5050508@redhat.com> <4BD0CBBF.1060300@redhat.com> <4BD1B1CA.5050502@redhat.com> <4BD1C0A4.6070102@redhat.com> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 To: linux-ext4@vger.kernel.org Return-path: Received: from mail-gy0-f174.google.com ([209.85.160.174]:50004 "EHLO mail-gy0-f174.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1757754Ab0DWPtI (ORCPT ); Fri, 23 Apr 2010 11:49:08 -0400 Received: by gyg13 with SMTP id 13so5204714gyg.19 for ; Fri, 23 Apr 2010 08:49:04 -0700 (PDT) In-Reply-To: <4BD1C0A4.6070102@redhat.com> Sender: linux-ext4-owner@vger.kernel.org List-ID: > Also note that having battery backed RAID cards does not mean that your > drive's write cache will survive a power outage. You need to use vendor > specific tools usually to poke at the drives and make sure that the write > cache on the S-ATA disks is properly disabled (unless the LSI firmware does > something to manage the write cache on the drives). The server is fully battery backed for up to 45 minutes. Also, LSI does provide tools to disable the cache when the BBU fails. Its one of the array config parameters.