Hitchhiker's Guide to Openbsd

abort Quit program without saving current changes. 
fdisk tricks and tips
●
fdisk(8) offers the ability to specify partitions both in raw sectors and in Cylinder/Head/Sector formats. 
Both options are given for a reason -- some tasks are easier accomplished one way, others the other way. 
Don't lock yourself into only using one option. 
●
A totally blank disk will need to have the master boot record's boot code written to the disk before it can 
boot. You can use the "reinit" or "update" options to do this. If you fail to do this, you can write a valid 
partition table with fdisk, but not have a bootable disk. You may wish to update the existing boot code 
anyway if you are uncertain of its origin. 
●
If your system has a "maintenance" or "diagnostic" partition, it is recommended that you leave it in place 
or install it BEFORE installing OpenBSD. 
●
For historical reasons, "q" saves changes and exits the program, and "x" exits without saving. This is the 
opposite of what many people are now used to in other environments. fdisk(8) does not warn before saving 
the changes, so use with care. 
14.3 - Using OpenBSD's disklabel(8)
What is disklabel(8)?
First, be sure to read the 
disklabel(8)
 man page. 
The details of setting up disks in OpenBSD varies somewhat between platforms. For 
i386
, 
amd64
, 
macppc
, 
zaurus
, and 
armish
, disk setup is done in two stages. First, the OpenBSD slice of the hard disk is defined using 
fdisk(8), then that slice is subdivided into OpenBSD partitions using disklabel(8). 
All OpenBSD platforms, however, use disklabel(8) as the primary way to manage OpenBSD partitions. Platforms 
that also use fdisk(8) place all the disklabel(8) partitions in a single fdisk partition. 
Labels hold certain information about your disk, like your drive geometry and information about the filesystems 
on the disk. The disklabel is then used by the bootstrap program to access the drive and to know where 
filesystems are contained on the drive. You can read more in-depth information about disklabel in the 
disklabel(5)
man page. 
On some platforms, disklabel helps overcome architecture limitations on disk partitioning. For example, on i386, 
http://www.openbsd.org/faq/faq14.html (5 of 34)9/4/2011 10:02:25 AM

---

14 - Disk Setup
you can have 4 primary partitions, but with 
disklabel(8),
 you use one of these 'primary' partitions to store all of 
your OpenBSD partitions (for example, 'swap', '/', '/usr', '/var', etc.), and you still have 3 more partitions available 
for other OSs.