Hitchhiker's Guide to Openbsd

Partition id ('0' to disable) [0 - FF]: [0] (? for help) 07
Now we define its starting and ending points: 
Do you wish to edit in CHS mode? [n]
CHS mode allows you to specify disk space in Cylinders, Heads and Sectors. Keep in mind that for modern hard disks, 
the CHS numbers are completely bogus, just three numbers that translate to a sector on the disk, which is translated to 
your drives physical geometry (which probably varies across the disk anyway). 
If you answer "y" here, you will be prompted for the starting and ending cylinder, head and sector. If you answer "no" 
here (as we will), you will be prompted for starting sector and the size. Editing by CHS is often easier when working 
around an existing partition, starting sector and size is often easier when you want to quickly create a partition of a given 
size. 
offset: [0] 63
The fdisk platforms need a one track gap before the first partition. One track is one "sectors per track" number of sectors, 
the last of the "geometry:" numbers. It is easy to get in the habit of entering "63" here, as it is common for modern IDE 
http://www.openbsd.org/faq/faq4.html (20 of 43)9/4/2011 10:01:58 AM

---

4 - OpenBSD 4.9 Installation Guide
and SATA disks, but not all disks will use this as the size of a track, common modern exceptions are SCSI and Flash 
disks. 
size: [0] 5g
Rounding to nearest cylinder: 10490382
The "Size" value can be the number of sectors (512 bytes each), or the desired capacity when followed by a "k", "m" or 
"g". When editing using offset and size, fdisk will round your partition so it ends on a cylinder boundary (OpenBSD 
doesn't care about this, and it is possible no modern OS cares about this, but some might have at one time). 
Now, let's look at our new partition: 
fdisk:*1> p
Disk: wd0 geometry: 4998/255/63 [80293248 Sectors]
Offset: 0 Signature: 0x0
Starting Ending LBA Info:
#: id C H S - C H S [ start: size ]
-------------------------------------------------------------------------------
0: 07 0 1 1 - 652 254 63 [ 63: 10490382 ] NTFS
1: 00 0 0 0 - 0 0 0 [ 0: 0 ] unused
2: 00 0 0 0 - 0 0 0 [ 0: 0 ] unused
3: 00 0 0 0 - 0 0 0 [ 0: 0 ] unused
fdisk:*1>
Note that the prompt now includes an "*", this means there are unsaved changes. 
We've now created our Windows partition. Note that this partition is so far just reserved space on the disk, it isn't 
formatted; no file system exists here. You will worry about that when you install Windows; we've accomplished our goal 
of reserving space for the Windows partition to be created later. 
Now we create our OpenBSD partition. In this case, the partition ID will be "A6". 
fdisk:*1> e 1
Starting Ending LBA Info:
#: id C H S - C H S [ start: size ]
-------------------------------------------------------------------------------
1: 00 0 0 0 - 0 0 0 [ 0: 0 ] unused