You need to check what partitions are currently being used ( the df -kl command should be sufficient for that). Note what partitions are being used and then go into format.

Pick the disk you want to put a new partition on.

EXAMPLE ONLY- YOUR SYSTEM MAY BE DIFFERENT:

# format
Searching for disks...done

AVAILABLE DISK SELECTIONS:
0. C0T0D0 <BLAH,BLAH,BLAH>
1. C0T1D0 < BLAH,BLAH,BLAH>

Specify disk (enter its number): 1
selecting c0t1d0
[disk formatted]

FORMAT MENU:
disk - select disk
type - select (define) a disk type
partition - select (define) a partition table
...

format> p

PARTITION MENU:
0 - change '0' partition
1 - change '1' partition
...
partition> p
(display the current table)

Note - you will never change partition 2 - leave it alone. (there are exceptions but very rarely)

Once you have the current table listed you can look at it and see if there is room on the disk (space left that has not been allocated to a partition ) by checking the total space (partition 2) versus what is in all the others. You can also check if there are any empty partitions for you to use. If there is nothing at all on this disk, then you can set up one of the partitions to use the whole disk (see any disk manager software you might be using for possible other partitions you might need to create for their needs).

With a raw partition you want to set the flag to wu.

Once you set the partition name (unknown will work) and the flag to wu, then you set the starting cylinder and the size. This is where you need to know what is already on the disk, if anything, so you do not overwrite another partition.

Once you get that, pick the label option and you should be done (since it's a raw partition you are attempting to make).