From owner-freebsd-hackers Sat Sep 15 11:56:29 2001 Delivered-To: freebsd-hackers@freebsd.org Received: from srv1.cosmo-project.de (srv1.cosmo-project.de [213.83.6.106]) by hub.freebsd.org (Postfix) with ESMTP id 75F1837B407 for ; Sat, 15 Sep 2001 11:56:25 -0700 (PDT) Received: from mail.cicely.de (cicely20 [10.1.1.22]) by srv1.cosmo-project.de (8.11.0/8.11.0) with ESMTP id f8FIuI609623; Sat, 15 Sep 2001 20:56:19 +0200 (CEST) Received: (from ticso@localhost) by mail.cicely.de (8.11.0/8.11.0) id f8FIukN18148; Sat, 15 Sep 2001 20:56:46 +0200 (CEST) Date: Sat, 15 Sep 2001 20:56:45 +0200 From: Bernd Walter To: Matthew Jacob Cc: Don Sullivan , freebsd-hackers@FreeBSD.ORG Subject: Re: Large disk (>1 TB) support in FBD4.3 ? Message-ID: <20010915205645.C17960@cicely20.cicely.de> References: Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline User-Agent: Mutt/1.2.5i In-Reply-To: ; from mjacob@feral.com on Sat, Sep 15, 2001 at 11:29:41AM -0700 X-Operating-System: NetBSD cicely20.cicely.de 1.5 sparc Sender: owner-freebsd-hackers@FreeBSD.ORG Precedence: bulk List-ID: List-Archive: (Web Archive) List-Help: (List Instructions) List-Subscribe: List-Unsubscribe: X-Loop: FreeBSD.ORG On Sat, Sep 15, 2001 at 11:29:41AM -0700, Matthew Jacob wrote: > > Don- too bad- I'm over in NAS in building N-258 and just took down the h/w > where we could test this (Alpha 4100 with 8 Qlogic cards && 8 150GB MegaDrive > RAID arrays)- We're excessing this equipment because the mass storage group's > work was terminated due to budgetary goop. > > Typically there's no problem in *recognizing* raw SCSI disk, or RAID units > that look like a SCSI disks- Mike or others will have to speak about how well > specifical supported RAID cards for FreeBSD will handle something that large. I'm not shure about recent SCSI definitions, but as long as a physical sector is sized at 512 Bytes and SCSI uses 32Bit unsigned numbers a (virtual) SCSI disk is limited to 2T. Maybe recent SCSI specs already defined a new set of read/write... > A more problematic issue is whether FFS can reliably handle > 1TB. We did some > tests with NetBSD at 1TB a couple of years ago- you have to use larger block > and frag sizes (we were using 32k/8k)- but I've never myelf gotten FreeBSD up > above 500GB. I was going to do so when the rather flakey h/w I was on above > was set to be excessed. If I'd known you needed the work done- I could have > kept it going a couple more weeks and we could worked on sorting it out. FFS in it's design can go up to 2G * fragsize - that means 2T with default fragsize of 1k. The Problem is that FreeBSD internaly uses 32bit signed Blocknumbers for 512Bytes/Block independend of it's physical size. This limits to 1T. I successfully build 600G partitions with vinum and I've heared of users running partitions near the 1T limit. -- B.Walter COSMO-Project http://www.cosmo-project.de ticso@cicely.de Usergroup info@cosmo-project.de To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-hackers" in the body of the message