From owner-freebsd-geom@FreeBSD.ORG Fri Sep 24 02:43:52 2004 Return-Path: Delivered-To: freebsd-geom@freebsd.org Received: from mx1.FreeBSD.org (mx1.freebsd.org [216.136.204.125]) by hub.freebsd.org (Postfix) with ESMTP id 1608416A4CE for ; Fri, 24 Sep 2004 02:43:52 +0000 (GMT) Received: from gromit.dlib.vt.edu (gromit.dlib.vt.edu [128.173.49.29]) by mx1.FreeBSD.org (Postfix) with ESMTP id BF75143D39 for ; Fri, 24 Sep 2004 02:43:51 +0000 (GMT) (envelope-from paul@gromit.dlib.vt.edu) Received: from hawkwind.Chelsea-Ct.Org (pool-151-199-91-61.roa.east.verizon.net [151.199.91.61]) by gromit.dlib.vt.edu (8.13.1/8.13.1) with ESMTP id i8O2hm7K006841 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-SHA bits=256 verify=OK) for ; Thu, 23 Sep 2004 22:43:50 -0400 (EDT) (envelope-from paul@gromit.dlib.vt.edu) Received: from [192.168.1.25] (zappa [192.168.1.25])i8O2hgld025417 for ; Thu, 23 Sep 2004 22:43:42 -0400 (EDT) From: Paul Mather To: freebsd-geom@freebsd.org Content-Type: text/plain Message-Id: <1095993821.5665.124.camel@zappa.Chelsea-Ct.Org> Mime-Version: 1.0 X-Mailer: Ximian Evolution 1.4.6 Date: Thu, 23 Sep 2004 22:43:42 -0400 Content-Transfer-Encoding: 7bit Subject: gstripe stripe size units? X-BeenThere: freebsd-geom@freebsd.org X-Mailman-Version: 2.1.1 Precedence: list List-Id: GEOM-specific discussions and implementations List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Fri, 24 Sep 2004 02:43:52 -0000 What are the units for the stripe size argument to gstripe's "-s" option? E.g., does "gstripe label -s 4096 ..." mean use a stripe size of 4096 bytes; 4096 512-byte blocks; or what? The man page isn't specific. What is a good suggested value for stripe size? Does anyone have any empirical results to share? Does it make sense to split the file system block size over the providers of the stripe when calculating the stripe size to use? E.g., for a 16 KB block size over two providers, make the stripe size 8 KB. Or, is geom_stripe I/O done in much larger transfers? (Usually, small transfers are poor for performance, arguing in favour of a larger, rather than smaller, stripe size.) Cheers, Paul. -- e-mail: paul@gromit.dlib.vt.edu "Without music to decorate it, time is just a bunch of boring production deadlines or dates by which bills must be paid." --- Frank Vincent Zappa