ioctl's and USB drives

[dragoran]

Leonard den Ottolander wrote:

>Hi,
>
>I noticed hdparm doesn't work well on external USB drives. Try a hdparm
>-I /dev/sda and see it fail with a "HDIO_DRIVE_CMD(identify) failed:
>Invalid argument". (I notice this on both a 2.4 and 2.6 kernel and with
>hdparm-6.1.)
>
>My question is whether this is a shortcoming in the usb-storage driver,
>or because of some shortcoming in the firmware of the external drive
>(case). Or is it because the usb-storage driver uses emulated SCSI and
>this is why these commands fail?
>
>I would like to get these commands to work so I can password protect
>these drives with the new security commands introduced in hdparm.
>
>Leonard.
>
>  
>
hdparm -I only works on IDE devices on my sata drive it does not work 
(/dev/sda1) but on the IDE drive (/dev/hda) it does.