stress testing disks

[Lyle]

I downloaded a fresh copy of stresslinux, put it on a usb key, and booted a Dell PowerEdge R720xd with 14 disks on a Perc H710P controller.

I enter "stress --hdd 14 --verbose" and not much happens on the disk lights. Then I tried "stress --hdd 200 --verbose" and again I don't see a lot of disk access.

Am I using the right command? Thanks....