smartctl on an USB disk

[Hugo Vanwoerkom <hvw59601@care2.com>]

Hi,

I can run smartctl on a SATA disk:

smartctl -d ata -A -v 194,unknown /dev/sda

but when I run it on a USB disk:

smartctl -d ata -A -v 194,unknown /dev/sdb

I get:

Smartctl: Device Read Identity Failed (not an ATA/ATAPI device)

But it *is* an ATA disk.

Anybody?

Hugo