Apple's Disk Utility wastes 128 MB of hard drive space for every partition it creates. On my PowerBook with a 40GB disk and three partitions (system, user, swap), this corresponds to about 1% of wasted space, or 384 MB. This is output from pdisk for that disk:
/dev/rdisk0 map block size=512
#: type name length base ( size )
1: Apple_partition_map Apple 63 @ 1
2: Apple_Free 0+@ 64
3: Apple_HFS Apple_HFS_Untitled_2 9961472 @ 262208 ( 4.8G)
4: Apple_Free 0+@ 10223680
5: Apple_HFS Apple_HFS_Untitled_3 4225792 @ 10485824 ( 2.0G)
6: Apple_Free 0+@ 14711616
7: Apple_HFS Apple_HFS_Untitled_4 63166384 @ 14973760 ( 30.1G)
8: Apple_Free 0+@ 78140144
Your output might look slightly different; for no appearant reason my two PowerBook's pdisk output varies a little. These Apple_Free parts are completely unnecessary and can be removed. I won't tell exactly how to repartition your drive, because if you can't figure out that yourself, you probably shouldn't do it, but I will give some hints on the way...
Here are a few things to keep in mind...
1: Apple_partition_map Apple 63 @ 1
Also, save 16 blocks (i.e. 8KB) at the end of the partition table:
5: Apple_Free Extra 16 @ 78140144
I don't know what the last 16 blocks are for, but they have been there since I used pdisk for the first time on my 9600 back in 1997.Mac OS X Hints
http://hints.macworld.com/article.php?story=20050505081959988