From owner-freebsd-fs Fri Mar 15 0:34:43 2002 Delivered-To: freebsd-fs@freebsd.org Received: from mail.fidnet.com (two.fidnet.com [216.229.64.72]) by hub.freebsd.org (Postfix) with SMTP id 68F7C37B419 for ; Fri, 15 Mar 2002 00:34:35 -0800 (PST) Received: (qmail 10788 invoked from network); 15 Mar 2002 08:34:34 -0000 Received: from beast.hexaneinc.com (HELO beast) (216.229.82.132) by two.fidnet.com with SMTP; 15 Mar 2002 08:34:34 -0000 From: "Matthew Rezny" To: "freebsd-fs@freebsd.org" Date: Fri, 15 Mar 2002 02:35:31 -0600 Reply-To: "Matthew Rezny" X-Mailer: PMMail 2000 Professional (2.10.2010) For Windows 2000 (5.0.2195;2) MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Subject: disks > 1TB Message-Id: <20020315083435.68F7C37B419@hub.freebsd.org> Sender: owner-freebsd-fs@FreeBSD.ORG Precedence: bulk List-ID: List-Archive: (Web Archive) List-Help: (List Instructions) List-Subscribe: List-Unsubscribe: X-Loop: FreeBSD.org I just bought a 3ware 7810 controller and 8 160GB drives, which in RAID5 yields 1.04TB (real TB). Having previously seen statements that FFS limit is 64TB, I expected this to work. Unfortunately I found that the number of sectors becomes an issue. Looking through the mailing list history I see this has come up before and it will take a lot to solve, more than the spare time I have this weekend. The quick solution is make a 1TB filesystem and let the extra .04TB go to waste rather than try to patch the whole system. However, there is a slight problem with this, which is limits in the disklabel tool. The disklabel structure which is stored on disk uses u_int32_t for the number of sectors in the device. The disklabel tool uses int when interpretting all numbers in the getasciilabel() function. This limits disklabel to 1TB devices. If the declaration on line 964 of disklabel.c is changed from "int v" to "u_int32_t v" then this limit is lifted. This change is safe since the actual value on disk is unsigned. Using unsigned in the input allow disklabel to work with devices up to 2TB. This allows creation of 1TB slices on devices >1TB so that at least part can be used in the meantime while we wait for the limit to be lifted elsewhere in the system. Also, I've seen one mention of 4TB systems in the mailing list archives. How was this done? Kernel patches, other trickery? To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-fs" in the body of the message