This is a view of disks statistics for the system (provided you have a 2.0 or later kernel with the proc filesystem compiled in).

Statistics are drawn from the /proc/stat file which supports up to 4 disks only, with SCSI having the highest priority. For example, if you have both a hda IDE and a sda SCSI disk, statistics will not be available for the IDE disk and only the SCSI disk will show at index 0.

If you have a 2.1 or above kernel, data is displayed in 2 tables:

For 2.0 kernels, only the statistics table is displayed.

2.4 kernels support need more testing: please report problems.

SCSI support is not very well tested, for lack of hardware: please report problems.