From owner-freebsd-isp Wed Mar 3 1:37:11 1999 Delivered-To: freebsd-isp@freebsd.org Received: from caladan.tdx.co.uk (caladan.tdx.co.uk [195.188.177.4]) by hub.freebsd.org (Postfix) with ESMTP id 9C9C514EBC for ; Wed, 3 Mar 1999 01:35:50 -0800 (PST) (envelope-from kpielorz@tdx.co.uk) Received: from tdx.co.uk (lorca-tx.tdx.co.uk [195.188.177.242]) by caladan.tdx.co.uk (8.9.3/8.9.3) with ESMTP id JAA09347; Wed, 3 Mar 1999 09:35:31 GMT Message-ID: <36DD0263.58D2C566@tdx.co.uk> Date: Wed, 03 Mar 1999 09:35:31 +0000 From: Karl Pielorz Organization: TDX - The Digital eXchange X-Mailer: Mozilla 4.5 [en] (WinNT; I) X-Accept-Language: en MIME-Version: 1.0 To: Grant Beckerleg Cc: freebsd-isp@FreeBSD.ORG Subject: Re: ECC formatting References: <000f01be6557$4c373840$0602cfc2@gromit.uk1.vbc.net> Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit Sender: owner-freebsd-isp@FreeBSD.ORG Precedence: bulk X-Loop: FreeBSD.org Grant Beckerleg wrote: > > Hello there, > I am trying to get a DPT 3444UW scsi controller to > allow me to format my RAID array for ECC - 528bytes per sector instead > of 512. > > The DPT 'Storage Manager' software does not allow the option for ECC > formatting. The drives used are IBM Ultrastar 9ES 4.5Gb and both IBM > and DPT say they are compatible with the card. > > I think it is a jumper setting on the hard drive that is required - > but neither company has taken the trouble to document this. I have the > jumpers set correctly for the scsi bus ID's. > > Any ideas people? This sounds like it might be a hardware issue? (And has little to do with FreeBSD :-) - Are you sure the drives will do 528 bytes per-sector? - I'd imagine this would have to be done transparently?! - Do you really need this if the drives are in a RAID array anyway? Most (if not all) current drives have their own hardware / transparent ECC code on the drive, which uses things like read-solomon coding to detect and correct errors - and cannot be switched off (AFAIK). I seem to vaguley remember hearing about 528 byte sectors, but I'd have to say in the grand scheme of 'keep it simple', and to ensure any future drives you have to use (to replace failed ones etc.) would be 'off the shelf' compatible, it would figure high on my "nice, but don't do it" list :-) -Kp To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-isp" in the body of the message