[CentOS] rsync question

Hi folks,

I've been trying to wrap my head around this for a bit, done my googling and archive searching but I still can't seem to 'get' it.

Here goes:

I've a spare drive in my CentOS5.1 box, which (for testing now) I mount manually under /mnt/backup

I want to backup the /home tree to that box nightly via rsync (cronjob), so I tried this:

rsync -avrogz /home/ /mnt/backup/

All goes well, but it seems that rsync is copying the files and compressing them into an archive....both the file structure and the archive exist. Is there a flag I'm missing, or is there a better, more efficient way to get this accomplished?

Thanks in advance, -Ray