The first thing the installer actually does is allow you to partition your disks.
You will now initialize the disk(s) that OpenBSD will use. To enable all available security features you should configure the disk(s) to allow the creation of separate filesystems for /, /tmp, /var, /usr, and /home. Available disks are: sd0 sd1 wd0.1 Which one is the root disk? (or done) [done] wd0
Note that the installer has identified the disks attached to this system. OpenBSD found three disks, 1 which it calls sd0, sd1, and wd0. Any drive beginning with "sd" is a SCSI disk, while any drive beginning with "wd" is an IDE drive. Count the drives that the installer found; is that the number of drives you have in this machine? If not, then OpenBSD did not find all of your hard drives. You probably have an unsupported hard drive controller.
In this example, we're going to use the IDE drive for the operating system and the SCSI drives for database files and home directories. Type "wd0" and press ENTER.
Do you want to use *all* of wd0 for OpenBSD? [no] yes
If you want to share a single hard drive between multiple operating systems, take a look at the next chapter. Right now, enter "yes" here.