Problem choosing a partition type Topic is solved

[mariol]

I have a 4 TB NTFS disk that first became corrupted while downloading a file as the PC shutdown from an electric shock when I connected my cellphone to it. Apparently a problem with the cable as even without the phone just moving the cable did it again.

I run chkdsk /f on the corrupted disk. It lost 3 TB of data. Then I kept using it, and after very little time it became RAW.

I run testdisk. It suggested an EFI GPT type. I accepted and run Analyze. After three days, it was at a 50 % and it displayed only two lines that began with UNKNOWN.

Searching on the internet, it seemed like Unknown was the result of a wrongly chosen partition type. Also, there was another message of another user who also had a Seagate disk like mine, with a similar situation. So I stopped, choose Intel and run Analyze again. It was much faster, in just a few hours it had finished.

The partition recovered however was only a few hundred gb big, 3 TB remained unallocated.

So I was wondering, it's that because I have chosen a wrong partition type? Or should I go with a deep search to try and recover the rest of the disk? And recovering the files it's another, separate operation? Thank you for your help.

I include below the log (of the second analyze, as the first was not completed):

Sun Jul 10 14:01:08 2022
Command line: TestDisk

TestDisk 7.2-WIP, Data Recovery Utility, June 2022
Christophe GRENIER <grenier@cgsecurity.org>
https://www.cgsecurity.org
OS: Windows 8 (9200)
Compiler: GCC 11.2, Cygwin32 3001.4
ext2fs lib: 1.45.3, ntfs lib: 10:0:0, reiserfs lib: none, ewf lib: 20140608, curses lib: ncurses 6.1
disk_get_size_win32 IOCTL_DISK_GET_LENGTH_INFO(\\.\PhysicalDrive0)=2000398934016
disk_get_size_win32 IOCTL_DISK_GET_LENGTH_INFO(\\.\PhysicalDrive1)=1000204886016
disk_get_size_win32 IOCTL_DISK_GET_LENGTH_INFO(\\.\PhysicalDrive2)=12000105070592
disk_get_size_win32 IOCTL_DISK_GET_LENGTH_INFO(\\.\PhysicalDrive3)=14000519642624
disk_get_size_win32 IOCTL_DISK_GET_LENGTH_INFO(\\.\PhysicalDrive4)=6001175126016
disk_get_size_win32 IOCTL_DISK_GET_LENGTH_INFO(\\.\PhysicalDrive5)=4000787030016
disk_get_size_win32 IOCTL_DISK_GET_LENGTH_INFO(\\.\C:)=999077438976
filewin32_getfilesize(\\.\D:) GetFileSize err Funzione non corretta.

filewin32_setfilepointer(\\.\D:) SetFilePointer err Funzione non corretta.

Warning: can't get size for \\.\D:
disk_get_size_win32 IOCTL_DISK_GET_LENGTH_INFO(\\.\E:)=6001039245312
disk_get_size_win32 IOCTL_DISK_GET_LENGTH_INFO(\\.\F:)=14000383328256
disk_get_size_win32 IOCTL_DISK_GET_LENGTH_INFO(\\.\G:)=2000396746752
disk_get_size_win32 IOCTL_DISK_GET_LENGTH_INFO(\\.\M:)=12000102973440
Hard disk list
Disk \\.\PhysicalDrive0 - 2000 GB / 1863 GiB - CHS 243201 255 63, sector size=512 - ST2000DM001-1ER164, S/N:Z4Z30A8W, FW:CC26
Disk \\.\PhysicalDrive1 - 1000 GB / 931 GiB - CHS 121601 255 63, sector size=512 - Samsung SSD 860 QVO 1TB, S/N:S4CZNF0M462613R, FW:RVQ01B6Q
Disk \\.\PhysicalDrive2 - 12 TB / 10 TiB - CHS 1458929 255 63, sector size=512 - WD Elements 25A3, S/N:8CKBDT4E, FW:1021
Disk \\.\PhysicalDrive3 - 14 TB / 12 TiB - CHS 1702132 255 63, sector size=512 - Seagate Expansion Desk, S/N:NAABCS6X, FW:0915
Disk \\.\PhysicalDrive4 - 6001 GB / 5589 GiB - CHS 91200 255 63, sector size=4096 - LaCie P9233, S/N:3XSC23LN0000, FW:1053
Disk \\.\PhysicalDrive5 - 4000 GB / 3726 GiB - CHS 486401 255 63, sector size=512 - TO Exter nal USB 3.0, S/N:2015033100081, FW:0104
Drive E: - 6001 GB / 5588 GiB - CHS 91198 255 63, sector size=4096 - LaCie P9233, S/N:3XSC23LN0000, FW:1053

Partition table type (auto): EFI GPT
Disk \\.\PhysicalDrive5 - 4000 GB / 3726 GiB - TO Exter nal USB 3.0
Partition table type: Intel

Analyse Disk \\.\PhysicalDrive5 - 4000 GB / 3726 GiB - CHS 486401 255 63
Current partition structure:

Partition sector doesn't have the endmark 0xAA55

search_part()
Disk \\.\PhysicalDrive5 - 4000 GB / 3726 GiB - CHS 486401 255 63
BAD_RS LBA=395828663 11834667
check_part_i386 failed for partition type 0B
FAT32 291988 138 46 316393 204 1 392070439
BAD_RS LBA=2435354200 5307357
check_part_i386 failed for partition type 01
FAT12 418943 34 60 670618 20 16 4043157950
This partition ends after the disk limits. (start=6730321496, size=4043157950, end=10773479445, disk end=7814037168)
Disk \\.\PhysicalDrive5 - 4000 GB / 3726 GiB - CHS 486401 255 63
Check the hard disk size: HD jumper settings, BIOS detection...
The hard disk (4000 GB / 3726 GiB) seems too small! (< 5516 GB / 5137 GiB)
The following partition can't be recovered:
FAT12 418943 34 60 670618 20 16 4043157950

Results
L FAT32 291988 138 46 316393 204 1 392070439
add_ext_part_i386: max
add_ext_part_i386: min

interface_write()
1 E extended LBA 291988 0 1 316393 254 63 392082390
5 L FAT32 291988 138 46 316393 204 1 392070439

[recuperation]

Did your 4 TB hard disk come with an external housing?
If yes, did you remove it from there?

[mariol]

No, it was rather an internal hard disk that I put into a case and used as external disk. At first I used it as an internal disk, but after it was 2.5 TB full, it began to give me I/O Errors. Since they were similar to the errors another disk on the same position had given me, I deduced that there was some trouble with some of the cables, so I put it as an external.

[recuperation]

You did not tell maker and model of your drive. Typically drives come with sectors that have a length of 512 bytes. The old MBR partition table type scheme can only address 2 TB given a sector length of 512 bytes.
If you were able to use more than 3 TB you must have used the GPT-scheme.

Rerun Testdisk based on the recommend selection and post the log file.

[mariol]

Thank you! I'll retry it. But, if it needs too many days I'll probably just format the disk. Thanks again for your help.