(Deep) search stopping on HDD despite adjusting geometry

Using TestDisk to repair the filesystem
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wasve
Posts: 2
Joined: 05 Oct 2024, 18:20

(Deep) search stopping on HDD despite adjusting geometry

#1 Post by wasve »

Hi all,
I have a seagate 2tb with quit some data that was in a TS251+ QNAP NAS (only 1 disk): the partitions were created when initializing the disk some years ago and don't have a dump/backup. A month ago the QNAP didn't recognized the disk anymore so i'm now trying to recover it from a windows PC as external drive via a USB case.
Originally it recognized the 2tb as a single "unallocated" space via some shareware tool (free version), and i tried hdd generator 2011 (free), but after first scan it only now shows up in testdisk or other similar software as a 4GB disk (which i guess was the size of the first partition if i remember correctly, but not the "big" one hosting my files & photos).
I tried to fix the geometry in testdisk by adjusting the number of cylinders to 243201 (found on the web), so that 243201 * 255 * 63 * 512b = 2TB nearly. However the "search" (and "deep search") stops after 503 cylinders, as if there was nothing beyond...
It then proposes to "add" a partition:as i don't have the original table, I have found a partition table from a qnap 2tb hdd online and tried to configure them on testdisk at this step, but it asks me to write it to the disk before doing the search and i'm not sure this is actually the right partition table...
I also tried adjusting the headers to 16 (and consequently the number of cylinders to match 2TB to the official number of sectors from my specific seagate disk datasheet), but wasn't more successful.

I tried PhotoRec but same issue, it doesn't scan beyond those 4Gb.
I also tried to run cygwin but on that disk i get the following error: fdisk: cannot open /dev/sdb: Invalid request code

Any idea on how to fix this? Thanks a lot!
recuperation
Posts: 2879
Joined: 04 Jan 2019, 09:48
Location: Hannover, Deutschland (Germany, Allemagne)

Re: (Deep) search stopping on HDD despite adjusting geometry

#2 Post by recuperation »

wasve wrote: 05 Oct 2024, 18:51 Hi all,
I have a seagate 2tb with quit some data that was in a TS251+ QNAP NAS (only 1 disk): the partitions were created when initializing the disk some years ago and don't have a dump/backup. A month ago the QNAP didn't recognized the disk anymore so i'm now trying to recover it from a windows PC as external drive via a USB case.
Originally it recognized the 2tb as a single "unallocated" space via some shareware tool (free version), and i tried hdd generator 2011 (free),
I don't know what "hdd generator" is. Is it a do-it-yourself-kit to produce one's own harddisks?
but after first scan it only now shows up in testdisk or other similar software as a 4GB disk (which i guess was the size of the first partition if i remember correctly, but not the "big" one hosting my files & photos).
I tried to fix the geometry in testdisk by adjusting the number of cylinders to 243201 (found on the web), so that 243201 * 255 * 63 * 512b = 2TB nearly. However the "search" (and "deep search") stops after 503 cylinders, as if there was nothing beyond...
A geometry adjustement in TestDisk only changes the partition table but it never changes the size of your storage device. If your storage device itself does not show its correct size you have to contact a professional recovery lab. Geometry data is not used by modern operating systems.


I tried PhotoRec but same issue, it doesn't scan beyond those 4Gb.
Did this yield any result?
I also tried to run cygwin but on that disk i get the following error: fdisk: cannot open /dev/sdb: Invalid request code

Any idea on how to fix this? Thanks a lot!
If the size of your storage device is not recognized correctly you will have to contact a professional recovery lab.
To exclude the possibility of your USB enclosure being the culprit for the size mismatch connect your device to the mainboard of a desktop computer. Only do this when your desktop computer is switched off.
wasve
Posts: 2
Joined: 05 Oct 2024, 18:20

Re: (Deep) search stopping on HDD despite adjusting geometry

#3 Post by wasve »

Thank you for your reply.

The software i was referring to is "HDD Regenerator 2011" (I forgot the "Re"). With PhotoRec i was unable to retrieve any file: but if i recall correctly the partition table, the first 4gb partition was not intended to store any user data...

Re the disk geometry indeed my goal was to force testdisk to "see" the real size of the storage device (2Tb) instead of what is currently read (4Gb). I have tried to connect my drive to another computer via another cable but it didn't change anything. If I find any similar 2Tb partition table from another QNAP and write it to my disk, will it then by chance help me to have my PC/testdisk "see" the 2Tb again instead of the 4Gb?
recuperation
Posts: 2879
Joined: 04 Jan 2019, 09:48
Location: Hannover, Deutschland (Germany, Allemagne)

Re: (Deep) search stopping on HDD despite adjusting geometry

#4 Post by recuperation »

Size is, what TestDisk states in its device list or what you can see in Windows Disk Management. And this size does not depend on anything written on your disk, including a partition table.

If the size of your storage device is not recognized correctly you will have to contact a professional recovery lab.
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