How do OS X Upgrades work?

[russell.h]

Well I really need to create a new partition on my hard drive, but I haven't been able to resize "Macintosh HD" because apparently some file that diskutil resizeVolume can't move is near the end of the partition.

As I intend to upgrade to Leopard as soon as it comes out, I'm thinking I might just wait until then. My question is, when you upgrade OS X does it back up all my current files somewhere, wipe the partition then start over, or does it actually just go through and update files in your current installation?

Or the short version: will upgrading to Leopard defragment my hard drive? Or will I have to back my stuff up manually, nuke the partition and start from scratch?

Thanks,

Russell

 

[squeeks]

the second one, it just updates the files, if you want to start over you have to do it yourself, im planing on it because i have a lot of apps on here that i dont use, that i just installed to try out, so im looking forward to starting over.