On a NetApp you can determine the disk speeds for drives in your Filer using the following command:
storage show disk –a
This will show all of the disks. Each disk has a unique identifier within the NetApp, indicated by a numeric sequence typically starting with a 2a, 2b, 3a, 3b, etc. You can obtain detailed information about each disk by showing disk with the unique identifier in the command. You can also see a listing of disks by volume using the following command (they will appear in the RPM column):
vol status -r
This will show a variety of statistics, including the disk type, speed, etc. The vol command can also be used to add spare disks, setup mirroring and a few other nifty features!