From owner-freebsd-stable@FreeBSD.ORG Tue Oct 31 23:35:22 2006 Return-Path: X-Original-To: freebsd-stable@freebsd.org 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 809C216A572 for ; Tue, 31 Oct 2006 23:35:22 +0000 (UTC) (envelope-from fredrik.widlund@qbrick.com) Received: from mxfep02.bredband.com (mxfep02.bredband.com [195.54.107.73]) by mx1.FreeBSD.org (Postfix) with ESMTP id DA85543DAC for ; Tue, 31 Oct 2006 23:34:54 +0000 (GMT) (envelope-from fredrik.widlund@qbrick.com) Received: from ironport.bredband.com ([195.54.107.82] [195.54.107.82]) by mxfep02.bredband.com with ESMTP id <20061031233427.CXCX9734.mxfep02.bredband.com@ironport.bredband.com> for ; Wed, 1 Nov 2006 00:34:27 +0100 Received: from c-077be255.06-2033-73746f12.cust.bredbandsbolaget.se (HELO [85.226.123.7]) ([85.226.123.7]) by ironport.bredband.com with ESMTP; 01 Nov 2006 00:34:26 +0100 Message-ID: <4547DD7E.4030509@qbrick.com> Date: Wed, 01 Nov 2006 00:34:22 +0100 From: Fredrik Widlund User-Agent: Thunderbird 1.5.0.7 (Windows/20060909) MIME-Version: 1.0 To: Ivan Voras References: <45470D95.5020801@qbrick.com> <454718DD.8060108@qbrick.com> <45471ACC.2030604@fer.hr> <4547421D.2010206@qbrick.com> <45477FCC.9050901@qbrick.com> In-Reply-To: Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit Cc: freebsd-stable@freebsd.org Subject: Re: SAS Raid - mfi driver X-BeenThere: freebsd-stable@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: Production branch of FreeBSD source code List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Tue, 31 Oct 2006 23:35:22 -0000 Yes, it forces writeback even when the controller has no BBU. Choosing WBack itself will default back to WThru. It's dangerous, but I guess it should be much less dangerous than using for example softupdates. We have little choice until our order of BBUs get here, since the performance degradation of wthru would make it unusable for us. Ivan Voras skrev: > Fredrik Widlund wrote: > >> Solved my issue with LSI 8480E without BBU. With "write: BadBBU", >> "cache: enabled", and "io: cached", performance rose to around 200MB/s >> from 20MB/s. >> > > I don't know what "BadBBU" is, but from some Googling it seems to be a > setting that overrides BBU detection, and enables write caching even if > the system believes BBU is broken or missing. If true, this may be > dangerous for data consistency. > > _______________________________________________ > freebsd-stable@freebsd.org mailing list > http://lists.freebsd.org/mailman/listinfo/freebsd-stable > To unsubscribe, send any mail to "freebsd-stable-unsubscribe@freebsd.org" >