To display bytes written, bytes read statistics of all partitions of the disks available in the system you can use iostat
.
Below is an example usage.
iostat -p -d 1
outputs will be like this:
Linux 2.6.8-2-k7 (hostname.com) 07/22/08
Device: tps Blk_read/s Blk_wrtn/s Blk_read Blk_wrtn
hda 10.03 18.39 179.74 438347774 4285350463
hda1 0.00 0.00 0.00 6258 5519
hda2 0.00 0.00 0.00 8 8
hda3 23.99 18.37 179.74 438026546 4285344936