From owner-freebsd-current@FreeBSD.ORG Fri Nov 2 10:31:40 2007 Return-Path: Delivered-To: freebsd-current@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id 92B7916A41B for ; Fri, 2 Nov 2007 10:31:40 +0000 (UTC) (envelope-from matrix@itlegion.ru) Received: from corpmail.itlegion.ru (corpmail.itlegion.ru [84.21.226.211]) by mx1.freebsd.org (Postfix) with SMTP id BCA5113C4A6 for ; Fri, 2 Nov 2007 10:31:39 +0000 (UTC) (envelope-from matrix@itlegion.ru) Received: (qmail 86746 invoked from network); 2 Nov 2007 13:30:45 +0300 Received: from unknown (HELO Artem) (192.168.0.12) by 84.21.226.211 with SMTP; 2 Nov 2007 13:30:45 +0300 X-AntiVirus: Checked by Dr.Web [version: 4.44, engine: 4.44.0.09170, virus records: 253279, updated: 2.11.2007] Message-ID: <038501c81d3b$6d6460b0$0c00a8c0@Artem> From: "Artem Kuchin" To: "Pawel Jakub Dawidek" , "Dag-Erling Sm??rgrav" References: <0fbb01c81be1$37e698f0$0c00a8c0@Artem> <863avptzir.fsf@ds4.des.no> <20071102095506.GC24455@garage.freebsd.pl> Date: Fri, 2 Nov 2007 13:15:51 +0300 Organization: IT Legion MIME-Version: 1.0 Content-Type: text/plain; format=flowed; charset="iso-8859-1"; reply-type=original Content-Transfer-Encoding: 7bit X-Priority: 3 X-MSMail-Priority: Normal X-Mailer: Microsoft Outlook Express 6.00.2900.3138 X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2900.3198 Cc: freebsd-current@freebsd.org Subject: Re: BIO_FLUSH on twe driver. Why is it not there? X-BeenThere: freebsd-current@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: Discussions about the use of FreeBSD-current List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Fri, 02 Nov 2007 10:31:40 -0000 >> > However, twe is working via scsi subsystem and the authour of gjournal >> > said somewhere that he has had implemeneted BIO_FLISH for scsi and he >> > specifically mentioned that he has tested twe and twa and they both >> > support BIO_FLUSH. >> >> twa(4) uses CAM, but twe(4) doesn't (and never has). > >That was my mistake. Someone told me (I think it was jhb@), that twe(4) >turns off write cache automatically when there is no battery, so >BIO_FLUSH isn't really needed and if there is a battery, it also isn't >really needed. It would be nice to hide the warning in this case >somehow, but for now you should be safe by simply ignoring the warning. Um.. If battry is not installed write can be enabled easily. Here is my setting: Unit Write Cache (Controller ID 0) Unit 2 [RAID 1] Enabled Is your phrase "it also isn't really needed' related to this case too? 'Cause you said if BIO_FLUSH is not there and write cache is bigger than gjorunal's cache there could be trouble. Cache on my controller is 64MB, what;s the size of gjournal's cache? -- Artem