I have a Seagate 3 TB external USB drive.
CrystalDiskInfo, for example, correctly sees the drive as a 3 TB drive.
However, HDD Raw Copy Tool shows that the drive is only 375.07 GB. Why?

If I clone this drive onto an 3 TB identical drive (which incorrectly also shows it to be 375.07 GB), will the whole 3 TB drive be cloned or only 375.07 GB?

It appears that you have taken the drive out of its enclosure and installed it inside your computer.

CrystalDiskInfo is getting the drive capacity from the physical drive via the ATA Identify Device command whereas the HDD Raw Copy Tool appears to be reading the logical partition information in sector 0. If you clone the drive sector-by-sector, then your clone will be an exact physical copy. However, if you attempt to make a logical clone of the partition, then this will fail.

The reason for this behaviour is that Seagate's external 3TB products are configured with 4KB LBAs. When you remove the drive from its enclosure, this exposes its native 512-byte LBAs. Therefore the partition appears to be 1/8th its actual size (3TB / 8 = 375GB).

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A backup a day keeps DR away.

Thank you for the reply. No actually, both 3 TB SATA drives (source and destination) are still in the enclosure with their USB interface. However, HDD Raw Copy Tool reads both drives as 375 GB.

Could you please clarify:

1. Would I get an accurate clone if I perform the cloning with both drives in the enclosure, even though HDD Raw Copy Tool reads the drive as 375 GB?
2. Would I also get an accurate clone if I take out only the source from the enclosure (connected as SATA), but not the destination drive?
3. What if I remove both source and destination drives and connect them as SATA? Would the destination drive be read correctly when put back in the enclosure?

TIA!

ISTM that the HDD Raw Copy Tool cannot work with 4KB LBAs. Therefore I wouldn't trust it.

Instead I would use Seagate's DiscWizard:
http://www.seagate.com/gb/en/support/do ... iscwizard/

DiscWizard is an OEM version of Acronis True Image.

You can see what is happening if you use the following command:

fsutil fsinfo ntfsinfo X:

... where X: is the drive letter.

http://ss64.com/nt/fsutil.html

_________________
A backup a day keeps DR away.

Seagate told me that the DiscWizard will not work with a drive that shows RAW.
(I am trying to clone the drive before attempting data recovery).

Is there another windows tool that can perform sector-by-sector copy on a drive with bad sectors?
BTW, going back to my 3 questions above; using such a tool, would all 3 scenarios work (both drives in enclosure; source as out of enclosure; source and destination out of enclosure)?

I prefer to not use ddrescue as I need to use my computer in Windows during the recovery (furthermore, I have problems reading these 3TB USB v3.0 drives with Linux)