From owner-freebsd-questions@FreeBSD.ORG Sat Aug 9 05:52:54 2014 Return-Path: Delivered-To: freebsd-questions@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [8.8.178.115]) (using TLSv1 with cipher ADH-AES256-SHA (256/256 bits)) (No client certificate requested) by hub.freebsd.org (Postfix) with ESMTPS id 523AC7D2 for ; Sat, 9 Aug 2014 05:52:54 +0000 (UTC) Received: from sdf.lonestar.org (mx.sdf.org [192.94.73.24]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (Client CN "mx.sdf.org", Issuer "SDF.ORG" (not verified)) by mx1.freebsd.org (Postfix) with ESMTPS id 2E16E213E for ; Sat, 9 Aug 2014 05:52:53 +0000 (UTC) Received: from sdf.org (IDENT:bennett@sdf.lonestar.org [192.94.73.15]) by sdf.lonestar.org (8.14.8/8.14.5) with ESMTP id s795qaq3022145 (using TLSv1/SSLv3 with cipher DHE-RSA-AES256-GCM-SHA384 (256 bits) verified NO); Sat, 9 Aug 2014 05:52:36 GMT Received: (from bennett@localhost) by sdf.org (8.14.8/8.12.8/Submit) id s795qaQS027351; Sat, 9 Aug 2014 00:52:36 -0500 (CDT) From: Scott Bennett Message-Id: <201408090552.s795qaQS027351@sdf.org> Date: Sat, 09 Aug 2014 00:52:36 -0500 To: kpneal@pobox.com Subject: Re: gvinum raid5 vs. ZFS raidz References: <201408020621.s726LsiA024208@sdf.org> <53DCDBE8.8060704@qeng-ho.org> <201408060556.s765uKJA026937@sdf.org> <53E1FF5F.1050500@qeng-ho.org> <201408070831.s778VhJc015365@sdf.org> <201408070936.s779akMv017524@sdf.org> <201408071106.s77B6JCI005742@sdf.org> <20140808193032.GA42189@neutralgood.org> In-Reply-To: <20140808193032.GA42189@neutralgood.org> User-Agent: Heirloom mailx 12.4 7/29/08 MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit Cc: freebsd-questions@freebsd.org X-BeenThere: freebsd-questions@freebsd.org X-Mailman-Version: 2.1.18 Precedence: list List-Id: User questions List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Sat, 09 Aug 2014 05:52:54 -0000 kpneal@pobox.com wrote: > On Thu, Aug 07, 2014 at 06:06:19AM -0500, Scott Bennett wrote: > > Even just as parity bits, those would amount to only one bit per > > eight bytes, which seems inadequate. OTOH, the 520 bytes thing is > > tickling something in my memory that I can't quite seem to recover, and > > Weren't those drives used on the AS/400? I never worked with the AS/400 and paid little attention to stuff about it, so I really don't know. I had assumed that they used the same disk drive lines that were used on the mainframes. IBM kind of abandoned sectored drives after the 1311 and switched to all count-data|count-key-data drives, so if the AS/400 used the drives being made at the time the AS/400 made its appearance in the market, then the 520 bytes stuff was in relation to non-IBM systems. OTOH, if IBM introduced a new line of drives for the AS/400, then they could have been sectored drives with 520-byte sectors. Scott Bennett, Comm. ASMELG, CFIAG ********************************************************************** * Internet: bennett at sdf.org *xor* bennett at freeshell.org * *--------------------------------------------------------------------* * "A well regulated and disciplined militia, is at all times a good * * objection to the introduction of that bane of all free governments * * -- a standing army." * * -- Gov. John Hancock, New York Journal, 28 January 1790 * **********************************************************************