Date: Thu, 20 Feb 2003 14:36:53 -0500 From: northern snowfall <dbailey27@ameritech.net> To: freebsd-questions@freebsd.org Subject: [Fwd: Re: different disk geometry] Message-ID: <3E552E55.90501@ameritech.net>
next in thread | raw e-mail | index | archive | help
-------- 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 <dbailey27@ameritech.net>
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 <z@reflection.net.ru>
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
Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?3E552E55.90501>