Hi,

I've been using my SATA to USB adapter successfully in the past years with several hard drives. But I'm having problems with a large 1 TB WD mobile hard-drive (WDC WD10JPVT).

Formatting the drive using the motherboard SATA connectors, results in the drive showing up as RAW when using the adapter (RAW 931 GB partition).
Formatting the drive with the adapter, results in the drive showing as RAW when connecting it to the motherboard (a 116.44 GB RAW partition, 815.07 GB of unallocated space).

When I format the drive using the motherboard SATA connectors and issue an fsutil fsinfo ntfsinfo command, here is what I get:


Now here is the output after formatting with the adapter:


Now would anyone be able to give a technical explanation to this? I'd just like to understand. Is my SATA to USB adapter crappy, or is it a limitation of all SATA to USB adapters in general? Is it because the hard drive is large? A new SATA feature not supported by the adapter?

Thanks!

The adapter's firmware is configured for 4096 Bytes Per Sector whereas the drive presents with 512 Bytes Per Sector when attached to a SATA port. This means that its capacity will appear to be 1/8th of what it was when inside the enclosure.

116.44 x (4096 / 512) = 931.52 GiB

You can also see the difference in the number of sectors.

0x747057ff sectors x 512 bytes per sector = 1 000 202 042 880 bytes

0x0e8e0aff sectors x 4096 bytes per sector = 1 000 202 039 296 bytes

_________________
A backup a day keeps DR away.

Thank you fzabkar, that was the answer I was looking for. Did a little furhter investigation myself, and found the real cause behind this. The disk uses Advanced Format, which SATA to USB adapters have a hard time adapting to it:

"Sector-size issues are becoming quite complex. Until late 2009, the vast majority of hard disks used 512-byte sectors, and that was that. In late 2009, disk manufacturers began introducing so-called Advanced Format (AF) disks, which use 4096-byte sectors. These first AF disks (and, AFAIK, all AF disks today) present an interface to the computer that shows each 4096-byte physical sector as being split up into eight 512-byte logical sectors. This conversion enables older tools, including many BIOSes, that were built with 512-byte assumptions, to continue to work. I don't know if your disk uses AF or not, but in either case, it almost certainly uses a 512-byte logical sector size, meaning that the interface to the OS should use 512-byte sectors.

Complicating matters is certain USB disk enclosures. Some of these enclosures do the reverse of what AF does: They take eight disk sectors and bundle them into one new 4096-byte sector. I'm not sure what the reasoning is behind this move, but one practical advantage is that disks larger than 2TiB can be used with the old MBR partitioning system. One major disadvantage is that a disk partitioned in one of these enclosures can not be used directly or in an enclosure that doesn't do this type of translation. Likewise, a disk prepared without this translation can't be used when it's transferred into such an enclosure."

http://superuser.com/questions/679725/h ... ector-disk

Hi fzabkar,

When the adaptor firmware changes the 512e emulation to 4096 bytes, should not it also divide the number of LBA by the same factor ? And, whould not one expect the total size to be the same in situations ?

fzabkar,

I think I got it mixed up. Here the OP is talking about partition sizes not disk size.

But, I have one question though. During the sata connection, the Operating system (OS) did recognize the partition set by the adaptor albiet with reduced size; the OS calculated the partition size using the sector number set by the adaptor, 0x000000000e8e0aff, (multiplied by 512). Which is one-eighth of the original size.


Why has not the reverse been true for the sata formated partition ? Why did not the OS use the sector number set by the sata connection (0x00000000747057ff) and multiply it by 4096 to get an 8 Tera byte size ? After all the MBR is located in the same place in both cases.

I don't know, but I suspect that the OS is smart enough to know that a partition can't be larger than the physical drive. It would be interesting to create a small partition, say 100GB, via SATA and then see how it is identified inside the enclosure.

_________________
A backup a day keeps DR away.