Hi,
I hope this it the right list to report issues like this.
I have a 2TB Seagate FreeAgent GoFlex Desk. That consists of a 3.5" SATA
hard disk in a case, which plugs into a base unit which has SATA connector
for the drive and USB 2.0 for connection to host computer. The USB 2.0
dock bundled with the drive has Seagate part number 9ZH9P9-RAA.
The 2TB drive actually has 3,907,029,168 (emulated) 512-byte sectors.
However, the USB 2.0 dock firmware reports one fewer than that. It reports
last LBA as 3,907,029,166, i.e. that the drive has 3,907,029,167 sectors.
So the USB 2.0 dock (VID:PID 0BC2:5071) has an off-by-one bug with its
READ CAPACITY response. It may be worth adding it to the Linux USB quirks
list.
Consequently, using tools like dd to image/clone the disk to/from another
2TB drive will fail, missing the last sector when restoring an image to
the GoFlex Desk. And missing whatever data is actually in the 3907029168th
sector on the GoFlex disk when creating an image. And causing MD5
checksums to differ.
The actual last sector on the GoFlex disk -- when connected via the USB
2.0 dock -- is accessible, but only via direct SCSI access (tools like
sg_dd and ddpt).
It's worth noting that Seagate's own "SeaTools for Windows" diagnostic
program has the opposite bug! SeaTools for Windows reports drives as
having one sector *more* than they actually have. So for my GoFlex Desk
with USB 2.0 dock, the program reports it as having 3,907,029,168 sectors.
With an older FreeAgent Xtreme 2TB USB drive which does report the correct
number of sectors, SeaTools reports that as having 3,907,029,169 sectors!
I contacted Seagate about this but frankly they seemed pretty clueless,
denying any problem.
Seagate also sell USB 3.0 and Firewire 800 docks, but I don't have either
to test.
I have attached lsusb -v output (with my drive's serial number redacted).
# sg_readcap /dev/sdc
Read Capacity results:
Last logical block address=3907029166 (0xe8e088ae), Number of
blocks=3907029167
Logical block length=512 bytes
Hence:
Device size: 2000398933504 bytes, 1907729.1 MiB, 2000.40 GB
Using ddpt to read actual last sector via the block device fails of course:
# ddpt if=/dev/sdc of=real_last_sector.bin bs=512 count=1 skip=3907029167
remaining block count=1
0+0 records in
0+0 records out
time to transfer data: 0.003198 secs
Early termination, EOF on input?
Using SCSI passthrough works:
# ddpt if=/dev/sdc iflag=pt of=real_last_sector.bin bs=512 count=1
skip=3907029167
1+0 records in
1+0 records out
time to transfer data: 0.000666 secs at 0.77 MB/sec
-- Mark
Bus 002 Device 003: ID 0bc2:5071 Seagate RSS LLC
Device Descriptor:
bLength 18
bDescriptorType 1
bcdUSB 2.00
bDeviceClass 0 (Defined at Interface level)
bDeviceSubClass 0
bDeviceProtocol 0
bMaxPacketSize0 64
idVendor 0x0bc2 Seagate RSS LLC
idProduct 0x5071
bcdDevice 1.55
iManufacturer 1 Seagate
iProduct 2 FA GoFlex Desk
iSerial 3 xxxxxxxx
bNumConfigurations 1
Configuration Descriptor:
bLength 9
bDescriptorType 2
wTotalLength 32
bNumInterfaces 1
bConfigurationValue 1
iConfiguration 0
bmAttributes 0xc0
Self Powered
MaxPower 2mA
Interface Descriptor:
bLength 9
bDescriptorType 4
bInterfaceNumber 0
bAlternateSetting 0
bNumEndpoints 2
bInterfaceClass 8 Mass Storage
bInterfaceSubClass 6 SCSI
bInterfaceProtocol 80 Bulk (Zip)
iInterface 0
Endpoint Descriptor:
bLength 7
bDescriptorType 5
bEndpointAddress 0x81 EP 1 IN
bmAttributes 2
Transfer Type Bulk
Synch Type None
Usage Type Data
wMaxPacketSize 0x0200 1x 512 bytes
bInterval 0
Endpoint Descriptor:
bLength 7
bDescriptorType 5
bEndpointAddress 0x02 EP 2 OUT
bmAttributes 2
Transfer Type Bulk
Synch Type None
Usage Type Data
wMaxPacketSize 0x0200 1x 512 bytes
bInterval 0
Device Qualifier (for other device speed):
bLength 10
bDescriptorType 6
bcdUSB 2.00
bDeviceClass 0 (Defined at Interface level)
bDeviceSubClass 0
bDeviceProtocol 0
bMaxPacketSize0 64
bNumConfigurations 1
Device Status: 0x0001
Self Powered
