Unable to access data after removing drive from external case and using as internal

[iluvdeal]

I was using a Seagate Backup Plus drive as a backup drive via USB. The USB drive was formatted in NTFS in Windows, I didn't run or install any weird Seagate software on it either.

I decided to to remove it from it's external case (which was a pain) and connected the hard drive internally to SATA for faster speeds. Windows can see the drive but thinks its uninitialized. As a test, I connected it back via its USB connection, Windows can then see the data on it using that USB connection.

Is Seagate using some sort of encryption via the USB connector? Is there any software out there to duplicate that behavior in Windows so I can access the data from it via SATA? If not, guess I'll have to copy data over USB to another drive, then format it once it's connected internally.

 

[greenhawk]

What size is the drive?

All of the larger external drives (2TB and above) have to have a special interface chip to work as USB is limited to 2TB addressable space on a attached device. By doing some shifty changes (larger sector size generally), larger drives can work, but you can not do what you have done and just pull the drive and expect it to work.

I have not heard of anyone having software to "fix it", but I would be surprised if there was not software around that could not do some data recovery. But as you have the external case still, best to do as you mentioned and copy it off , format and then use it as you want.

For all the trouble though, and espically if you do not have the needed space, getting a internal drive instead of using the pulled apart external drive might be far less hassles.

 

[Cerb]

Seagate is using a non-standard partitioning setup. Windows expects 512B sectors in MBR, but Seagate is using 4096B. Just copy the data, and then treat the drive as unpartitioned/FUBAR, once you remove it.

 

[iluvdeal]

It's a 3TB drive. I didn't know about the 2TB limitation on drives accessed via USB and the interface chip to get around that. Had I known, I'd never have used it as a USB drive from start since converting it into internal was always a part of the plan. You learn something new everyday, thanks guys.

 

[Cerb]

It's a 3TB drive. I didn't know about the 2TB limitation on drives accessed via USB and the interface chip to get around that.

The limitations are not of USB access, but of either the specific chips used, or Windows XP compatibility.

Modern HDDs are what has been termed "512e" (512B sector emulation). They have physical sectors that are 4096B in size, but logically present 512B sectors. File systems generally use 4KB sector (cluster, in Windows terms) sizes, so access aligned to 4KB addresses will read and write entire physical sectors. In that way, not much code needs changing.

MBR, the partitioning scheme we've used since way back in the DOS days, is limited to 2TB, with 512B sectors. Windows Vista and up support GPT, which gets around the limit (but still expects 512B logical sectors, for the time being).

Windows does not support 4KB sector ATA HDDs, but it does support 4KB sector USB mass storage devices.

Many USB bridge chips cannot use 48-bit LBA addresses, so can't address >2TB drives internally, with 512B sectors.

Since the drives are 4096B native, using that instead of the legacy/regular 512B, allows for 16TB, instead of 2TB. So, they can use that as a hack to (a) use USB bridge chips that are cheaper, due to being phased out as legacy, and (b) have XP compatibility with big drives. But, if you plug it in internally, Windows expects 512B sector sizes, so everything looks like garbage when it tries to read it, becase it's off by a factor of 8, compared to being in the USB bridge.

 

[phis6]

Many USB bridge chips cannot use 48-bit LBA addresses, so can't address >2TB drives internally, with 512B sectors.

Since the drives are 4096B native, using that instead of the legacy/regular 512B, allows for 16TB, instead of 2TB. So, they can use that as a hack to (a) use USB bridge chips that are cheaper, due to being phased out as legacy, and (b) have XP compatibility with big drives. But, if you plug it in internally, Windows expects 512B sector sizes, so everything looks like garbage when it tries to read it, becase it's off by a factor of 8, compared to being in the USB bridge.

This totally explains the whole thing...:thumbsup: