partitioning help

I want to partition my internal HD to install linux. I'm currently running OS X 10.4. According to this and this I have to use that diskutil command to partition and avoid wiping out my hd. However when I tried it terminal responded with this: Resizing encountered error The underlying task reported failure on exit (-9972) on disk disk0s2 Macintosh HD.
I was reading some threads here and for the most part I found nothing that could help me except apart from maybe I should have defragmented my drive. Given terminal's output, can I deduce that partitioning didn't occur and my drive isn't damaged (I mean I doubt given that I'm on my laptop right now and disk utility isn't showing me anything weird. But I want to be extra careful considering I know squat about using terminal) as a result of this attempt?

 

The first link tells me that to make partitions on Tiger using Disk Utility I'd have to erase the current partitions on my HD. I have the important things backed up but I'd rather not have to reinstall my OS (I mean I have the install disk but it's 10.4.8...does Apple still have the subsequent updates available for dl?).