On Wednesday May 6 2009, Greg Freemyer wrote:
On Wed, May 6, 2009 at 4:47 PM, Randall R Schulz <rschulz@sonic.net> wrote:
On Wednesday May 6 2009, Larry Stotler wrote:
On Wed, May 6, 2009 at 2:18 PM, Randall R Schulz wrote:
...
However, whether a drive is connected by SATA, eSATA, USB, FireWire, SCSI, SAS or IDE / ATA, it is still and equally "directly" connected.
Not if there is some other problem.
I guess I don't know what you mean by "direct." In all these cases there is an electrical connection between the device and the computer that conveys power and the control and data signals. What can be more "direct" than that?
Well, usb is a scsi protocol transport (T10), not a ata protocol transport (T13).
So the linux kernel sends scsi commands to the usb adapter. It has a SAT device (scsi to ata translator) that turns those into ata commands and sends those to the drive.
So a bug in the SAT device can cause the drive to not work correctly. I don't consider that a direct connection.
There are multiple junctions and controllers between the CPU (or even the "south bridge" or equivalent) and the peripheral device regardless of the connector or protocol involved and all of them must be controlled and configured by software running on the main CPU.
Greg
Randall Schulz -- To unsubscribe, e-mail: opensuse+unsubscribe@opensuse.org For additional commands, e-mail: opensuse+help@opensuse.org