Hello everyone,

So I screwed up. It was such a simple mistake but I sicker-punched myself anyway.

While preparing a new Raspberry Pi for operation via writing the image to a TF card, I selected my backup external HDD by mistake. While that was bad enough, the write operation caused the drive to forget it's actual size and now it things it's a 1800 GB drive instead of the 4000GB it used to have (Linux lists it as 1800/1678.) Seagate has essentially washed their hands of the thing calling it 'corrupted'. Is there any help for me, to get the other 2200 GB back? So far I've tried rebuilding the partition table, switching it between MBR and GPT types, performing data cleaning processes, all in Windows 10 and Linux. I think I need a tool that will re-flash the firmware to tell the drive how much space it's supposed to have so that I can allow the various drive checking tools to look for 'bad sectors' and exclude them but the only thing I've found that seems like it'd do that was a piece of software from this site that promised to do a LLF but instead blue-screened my machine during install...

I'm not trying to recover the old data, it's was a backup anyway and the tools I had couldn't pull any useful files from it shortly after the event. Lots of file 'names' with content but no complete/useable files.

Thanks in advance for suggestions,
Landon

It appears that there is a 32-bit LBA limitation in the BIOS or SATA driver or USB firmware.

4TB - 2TiB = 1.80TB = 1677GiB

What capacity is reported by CrystalDiskInfo?

_________________
A backup a day keeps DR away.

that seems like a helpful start... Any idea how could this have been caused by an iso write operation, and how I might change it back? This drive and USB enclosure have worked well for years before this happened.

Thanks,
Landon

That sounds pretty much right... The question is, how did an ISO write cause it and how do I get it set back to the correct functionality?

As for CrystalDiskInfo, I'll do that once the deep scan I started yesterday finishes. Hopefully by week's end. =\

Thanks,
Landon

Here we go...

As you can see, the drive is reporting its full capacity via the Identify Device command (via ATA pass through). However, the OS is seeing a reduced capacity due to a 32-bit LBA limitation in the firmware in your USB-SATA external enclosure. There is nothing you can do except to update the firmware for your enclosure, or purchase a more recent enclosure.

_________________
A backup a day keeps DR away.

I still don't understand how an ISO write could change the firmware of the USB interface. I'll attempt using a different SATA adapter next but this asnwer doesn't make sense to me.

Landon

In fact, the new adapter does allow me to access the whole capacity... I'll be seeing about updating that firmware I guess.

Thank you,
Landon

Could you show us the Partitions window in DMDE?

https://dmde.com/

_________________
A backup a day keeps DR away.

Well,
Its a 4TB HDD And The Image You Overwrote The Initial Sectors Has a MBR Type Partition And Due To This Its Reporting This Capacity ,You Can Change The End Signatures Of This Sector 0 And Restart The HDD ,Its Not a Bug Of Your USB And Its Being Pointed Out ,Or You Can Simple Write 00 in The Sector No 0

_________________
Regards
Amarbir S Dhillon , Chandigarh Data Recovery Labs [India]
Logical,Semi Physical And Physical Data Recovery
Website-> http://www.chandigarhdatarecovery.com

See attached...

It does appear that the enclosure has a 32-bit LBA limitation, even with a GPT partition.

_________________
A backup a day keeps DR away.

Frustratingly, I have enough knowledge for about half of what you're suggesting to make sense. I do not know how to directly write to sector 0 but I have already attempted initializing the drive to GPT. I am able to see and format the full drive space using another USB interface though so I still don't understand how writing to the drive is going to change something.

Is there a specific utility I need to do the sector write?

Thanks,
Landon

I see no evidence that your drive ever had a 4TB NTFS volume.

If you double-click the second New Volume and expand the $Root, do you see your original file/folder structure?

_________________
A backup a day keeps DR away.

I don't actually know what I'm looking for but here's the display. I wouldn't expect it to show though... at this point I've done several deep-scan operations and I think one over-write trying to get any tool to notice that the drive has extra bits to write to.

Thanks,
Landon

I suspect that if you partition and format your drive inside your PC, or in your other enclosure, and then attach it to your USB-SATA bridge, you will see the full capacity in Disk Management. This may be how you got it to work previously. However, you must not use the drive in this way, as you will have created a time bomb. Everything will appear to work fine until you hit the 2TiB point. When this happens, any further data that you write will wrap around to sector 0 and corrupt your file system.

_________________
A backup a day keeps DR away.

That is entierly possible. I seem to remember the drive only being up to 1.6TB when I last checked it. I don't know that it has ever been formatted since being installed in the old enclosure. I guess it's time to buy a new enclosure and use this one for one of the old (smaller) drives I have laying around.

Thanks,
Landon