[Cialug] The kernel and my hard drive

[Jeff]

Newbie here
Thank you for your help making me feel comfortable with my new operating
system
I am curious as to how important it is to keep up the kernel. Running
Ubuntu 6.10, it has a different kernel build than what is available now.
When the new version of Ubuntu, 7.04, comes out, is it to my benefit to
upgrade to that, or is staying with the 6.10 advantageous for right now.
And my hard drive. Is there a utility like disk clean-up or defrag for
Linux or just how does that work.
Again, thanks for the help.