From owner-freebsd-questions Thu Feb 20 12: 0:18 2003 Delivered-To: freebsd-questions@freebsd.org Received: from mx1.FreeBSD.org (mx1.freebsd.org [216.136.204.125]) by hub.freebsd.org (Postfix) with ESMTP id E7FBC37B401 for ; Thu, 20 Feb 2003 12:00:16 -0800 (PST) Received: from mailhost.det3.ameritech.net (mailhost2-sfldmi.sfldmi.ameritech.net [206.141.193.106]) by mx1.FreeBSD.org (Postfix) with ESMTP id 2FD5E43FB1 for ; Thu, 20 Feb 2003 12:00:16 -0800 (PST) (envelope-from dbailey27@ameritech.net) Received: from ameritech.net ([67.38.15.139]) by mailhost.det3.ameritech.net (InterMail vM.4.01.02.17 201-229-119) with ESMTP id <20030220193739.RFVO176.mailhost.det3.ameritech.net@ameritech.net> for ; Thu, 20 Feb 2003 14:37:39 -0500 Message-ID: <3E552E55.90501@ameritech.net> Date: Thu, 20 Feb 2003 14:36:53 -0500 From: northern snowfall User-Agent: Mozilla/5.0 (X11; U; SunOS sun4u; en-US; rv:0.9.4.1) Gecko/20020518 Netscape6/6.2.3 X-Accept-Language: en-us MIME-Version: 1.0 To: freebsd-questions@freebsd.org Subject: [Fwd: Re: different disk geometry] Content-Type: text/plain; charset=KOI8-R; format=flowed Content-Transfer-Encoding: 7bit Sender: owner-freebsd-questions@FreeBSD.ORG Precedence: bulk List-ID: List-Archive: (Web Archive) List-Help: (List Instructions) List-Subscribe: List-Unsubscribe: X-Loop: FreeBSD.ORG -------- Original Message -------- From: - Thu Feb 20 14:28:55 2003 X-Mozilla-Status: 0001 X-Mozilla-Status2: 00000000 Message-ID: <3E552C72.4040808@ameritech.net> Date: Thu, 20 Feb 2003 14:28:50 -0500 From: northern snowfall User-Agent: Mozilla/5.0 (X11; U; SunOS sun4u; en-US; rv:0.9.4.1) Gecko/20020518 Netscape6/6.2.3 X-Accept-Language: en-us MIME-Version: 1.0 To: Michael Soboleff Subject: Re: different disk geometry References: <000901c2d8f0$6e8fe570$0d01a8c0@yp.local> Content-Type: text/plain; charset=KOI8-R; format=flowed Content-Transfer-Encoding: 7bit > > >I have 40Gb IBM IDE drive, while booting freebsd 4.7 shows >me 79780/16/63 geometry, >but! sysinstall gives me another numbers : 5005/255/63. The >QUESTION is it OK? > Usually, what sysinstall gives is ok. Just make sure the number of sectors that sysinstall perceives is the same as or under the actual sector number. You can check by doing: 79780 * 16 * 63 = 80,418,240 sectors (512eight-bit octets each) 5005 * 255 * 63 = 80,405,325 sectors Any array of proper C/H/S can be given. What actually happens here is that Sysinstall determines the total amount of sectors on the disk (most likely in LBA mode), then determines the C/H/S based on most-likely-candidate mapping. 63 is maximum value for sectors per head. 255 is the maximum value for heads per cylinder. Thus, (Total_Sectors / (nHeads * nSectors)) = nCyls. If you are unhappy with Sysinstall's chosen mapping due to loss of X number of sectors, consult your hard disk's documentation to determine the valid C/H/S value or total sector number. Edit as appropriate. As a side note, don't give a number that exceeds the total number of sectors on the disk. The driver may attempt to access these sectors expecting OK from the controller, but, receiving ERROR. This may cause the driver to tell you something more malicious is occuring than is not, causing trouble down the road. Don To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-questions" in the body of the message