Native command which can be used for it for RedHat is vmstat.
It will provide you enough details about what's going on with your system (help to define performance problems as well). However output won't be as 'nice' as one from top with % numbers and it's not as specialized as iostat
I strongly advice to read man page - let us know if you have any questions about it.
Going back to iostat - it's very powerful tool.
As you are using RAID - you need to understand difference between naming conventions. Eg:
cciss/c0d0p1 should be extended to /dev/cciss/c0d0p1
cX == controler number
dX == disk number
pX == partition number
You can read about it more eg. here:
HP Smart Array CCISS driver
On top of it you are using LVM. To get more information about your devices you can use commands like:
vgdisplay (you will see volume groups)
lvdisplay (you will see logical volumes)
pvdisplay (you will see phisical volumes - which you probably want to get at this moment).
Regards,
-Artur.