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Old 9th October 2008
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Quote:
Originally Posted by bsdnewbie999 View Post
1: I have total size of 60GB hard disk.
That is approximately 117 million sectors. (You did not show the complete fdisk output, which includes the number of sectors and the disk geometry.) Your two MBR partitions on the drive extend through LBA 61432560, so only about 30GB of your 60GB is allocated in MBR partitions.

Disk geometry (cylinder / head / sector ) is no longer as critical as it once was long ago, as all modern drives have on-board electronics that manage their own physical geometry, which vary greatly. Most EIDE/ATA/SATA drives inform their controllers they have a cylinder geometry containing 255 read/write heads and 63 sectors per track, which has nothing to do with their internal physical geometries.

Even so, many BIOSes and OSes rely on MBR partitions starting on cylinder boundaries. However, note that Partition #0 does not start at the beginning of cylinder #0, but starts at the beginning of the second track. The first track (63 sectors) is reserved for the MBR and related structures. If the disk has a BSD disklabel, it can be found in here as well.

OpenBSD's fdisk(8) gives you complete control of MBR partitioning. You must set your OpenBSD MBR partition to start on a cylinder boundary.

Primary partition #0 is your Windows NTFS C: drive
Primary partition #1 is an area reserved for extended partitions. I can only guess that your "deleted" D: drive may have been configured as an extended partition. If so, be aware that deleting the extended partition does not delete this reserved area.

If you have no extended partitions any longer, or do not need any, you may delete this extended partition (editing any partition and setting its ID to 0 will mark the partition unused. You may also reuse the partition and/or resize it.

OpenBSD MBR partitions use Partition ID A6.

You may keep Partition #1 as is, or reuse it, or mark it unused and select another primary partition for OpenBSD. In all cases, you will want to edit in CHS mode. (See the -e option in the fdisk(8) man page.)

Partition #0 uses cylinders 0-3470, and Partition #1 uses cylinders 3471-7294.

If you are replacing Partition #1 with an OpenBSD partition, edit the partition, set the partition ID to A6, request editing in CHS mode, and leave its starting cylinder as 3471. Set its ending cylinder wherever you want. The partition editor will show you the ending cylinder number, and, if you select it, will show you the final head/sector numbers, which may be shorter than 255/63.

If you are keeping Partition #1, edit Partition 2 or 3, and set its starting cylinder to 7295.
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