Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S265474AbTFMSHG (ORCPT ); Fri, 13 Jun 2003 14:07:06 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S265475AbTFMSHG (ORCPT ); Fri, 13 Jun 2003 14:07:06 -0400 Received: from fmr02.intel.com ([192.55.52.25]:64213 "EHLO caduceus.fm.intel.com") by vger.kernel.org with ESMTP id S265474AbTFMSHD (ORCPT ); Fri, 13 Jun 2003 14:07:03 -0400 Message-ID: From: "Cress, Andrew R" To: "'Matthias Andree'" , Linux-Kernel mailing list Subject: RE: SCSI Write Cache Enable in 2.4.20? Date: Fri, 13 Jun 2003 11:25:43 -0700 MIME-Version: 1.0 X-Mailer: Internet Mail Service (5.5.2653.19) Content-Type: text/plain Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1801 Lines: 48 IMO, it isn't "necessary", but it is very desirable, and should be the default, to disable write cache on SCSI disks for any system that is concerned about reliability. If reliability is less important than performance, and you have more sequential writes than random writes, then you would get a performance boost, and those (limited) cases might want to turn write cache on. Disk benchmark apps are one example. However, most environments have a lot more small random writes than sequential writes, and so don't even see a performance improvement from turning disk write cache on. The OS type or version shouldn't affect this, in principle. Andy -----Original Message----- From: Matthias Andree [mailto:matthias.andree@gmx.de] Sent: Thursday, June 12, 2003 5:25 AM To: Linux-Kernel mailing list Subject: SCSI Write Cache Enable in 2.4.20? Hi, I haven't followed the status of write barrier patches recently, I am wondering if it's still "necessary" (to avoid file system corruption) to disable the write cache of a SCSI disk drive when the machine doesn't have an uninterruptible power supply or if instead the file systems and driver know how to use ordered tags. (Fujitsu MAP drive: 8 MB cache, AIC7880 adapter, SuSE Linux 8.2 patched 2.4.20 kernel with ext3 and xfs) TIA, -- Matthias Andree - 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/ - 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/