How to see individual hard drive read/write status?
yum install sysstat
iostat can be useful too, e.g. iostat -dx 5
if you want to see the raw transfer rates rather than the i/o stats, you can do:
iostat -k 10 10
which will update 10 times, once every 10 seconds. I personally prefer iostat -x like gordon recommended, but iostat -k is easier to read the M/s
