Chiaki wrote:
It is very possible that the USB<-> ATA(SCSI?) bridge
may not be clever/powerful enough to
understand the emulated SCSI protocol correctly.
I have a I-O HDH-U USB external disk drive
with USB<->ATA bridge inside. (Don't know whether
the manufacrer is the same as yours, but it looks to
be the same manufacturer.)
Obviously S.M.A.R.T. information could not be
passed across this bridge until last April this year.
I-O Device, the manufacturer, issued an upgrade
of the bridge firmware last month, and now at least a particular
S.M.A.R.T.-aware program under Windows XP
can read the S.M.A.R.T. information
from the ATA disk in the external enclosure. Go figure.
Dario Oliva wrote:
I am trying to use the SG_IO ioctl from the scsi driver to read and
write raw
data to this USB hard drive (IO Data USB HD). I have googled the
device name and
only came up with 13 sites, none of which had any information for
this problem.
This is a link to a reseller in California who sells the device I am
using
http://www.devicenet-usa.com/product_en.html#hdp
To verify that the data was not being written from the device or read
from the device,
I used a protocol analyzer connected to the hard disk While sending
the read or write
commands using SG_IO, there was no activity on the disk. I have also
used a program I wrote
that reads individual sectors from a disk and displays the data in a
format similar to hexdump.
The output from that program is also attached, in the file named
data. As you will see, I did a read
several times from sector 0, receiving different slightly different
values every time.
I am attaching output from dmesg gathered while connecting and
reading from the device.
Where should I go from here? Are there other debug messages I can
enable within the scsi generic drivers.
Dario Oliva
Thanks for all the input. I was able to use sg_dd to figure out how
that program was sending the SCSI read10 command compared to
how I was sending it. I was setting the control byte (byte 9 in the 10-byte
command structure) to 1, and should have been setting it to 0.
After setting it to 0, everything worked fine.
Dario Oliva
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