Messages in this thread |  | | Date | Sat, 15 Jun 1996 12:52:14 +0200 | From | Andries.Brouwer@cwi ... | Subject | Re: My SCSI HD has 34 heads, not 255... |
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Thomas E Zerucha:
: Is it the kernel's job to return some random number, or to return the : correct geometery?
There does not exist a correct geometry. The numbers of heads, sectors, cylinders are a fiction for SCSI disks, and various systems and controllers use different fictions.
Linux does not use CHS at all, so, except when booting or using fdisk it does not matter (for Linux) what geometry you invent.
: Which of my four systems should I run the FDISK on?
Doesn't matter. It will run fine on all of them.
: Running the linux fdisk to create a : new linux partition anywhere else would destroy the DOS partition.
I don't think so. (And `the' linux fdisk is undefined. There are several.)
:: If you really need to use LILO or FDISK, they both provide options :: to handle this case. If you are just accessing file systems, :: where's the problem?
: This functionality is not documented (for fdisk) in the manpage, nor : online.
Hmm. For fdisk 3.04: ... -C cylinders Specify the number of cylinders, possibly overriding what the kernel thinks.
-H heads Specify the number of heads, possibly overriding what the kernel thinks.
-S sectors Specify the number of sectors, possibly overriding what the kernel thinks. ...
For fdisk 2.1: ... If possible, fdisk will obtain the disk geometry automatically. This is not necessarily the physical disk geometry, but is the disk geometry that MS-DOS uses for the partition table. If fdisk warns you that you need to set the disk geometry, please believe this statement, and set the geometry. This should only be necessary with certain SCSI host adapters ... ...
For cfdisk: ... cfdisk first tries to read the geometry of the hard disk. If it fails, an error message is displayed and cfdisk exits. This should only happen when partitioning a SCSI drive on an adapter without a BIOS. To correct this problem, you can set the cylinders, heads and sectors-per- track on the command line. ...
No reason to use kernel patches as a substitute for reading the docs.
Andries
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