Recover MAC Partition from FAT32 Reformat

How to use TestDisk to recover lost partition
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elcsum
Posts: 1
Joined: 18 Apr 2024, 18:15

Recover MAC Partition from FAT32 Reformat

#1 Post by elcsum »

I need help. I accidentally reformatted my 2TB Sandisk Extreme Portable SSD external. I believe I originally formatted the drive to MAC OS extended (journaled) and then selected the wrong drive and formatted the thing to FAT32. I have tried using TestDisk to recover with no luck and I think it may be in the settings I am using. I would appreciate any help. Here are me logs...

Wed Apr 17 21:08:31 2024
Command line: TestDisk

TestDisk 7.2, Data Recovery Utility, February 2024
Christophe GRENIER <grenier@cgsecurity.org>
https://www.cgsecurity.org
OS: Darwin, kernel 23.4.0 (Darwin Kernel Version 23.4.0: Wed Feb 21 21:44:31 PST 2024; root:xnu-10063.101.15~2/RELEASE_X86_64) x86_64
Compiler: GCC 4.2
ext2fs lib: none, ntfs lib: none, reiserfs lib: none, ewf lib: none, curses lib: ncurses 6.0
Hard disk list
Disk /dev/disk2 - 2000 GB / 1863 GiB - 3907028992 sectors (RO), sector size=512
Disk /dev/disk3 - 256 GB / 238 GiB - 500118192 sectors (RO), sector size=512
Disk /dev/disk4 - 256 GB / 238 GiB - 500118192 sectors (RO), sector size=512
Disk /dev/disk6 - 51 MB / 48 MiB - 100000 sectors (RO), sector size=512
Disk /dev/disk7 - 250 GB / 232 GiB - 488570880 sectors (RO), sector size=512
Disk /dev/rdisk2 - 2000 GB / 1863 GiB - 3907028992 sectors (RO), sector size=512
Disk /dev/rdisk3 - 256 GB / 238 GiB - 500118192 sectors (RO), sector size=512
Disk /dev/rdisk4 - 256 GB / 238 GiB - 500118192 sectors (RO), sector size=512
Disk /dev/rdisk5 - 361 MB / 345 MiB - 706561 sectors, sector size=512
Disk /dev/rdisk6 - 51 MB / 48 MiB - 100000 sectors (RO), sector size=512
Disk /dev/rdisk7 - 250 GB / 232 GiB - 488570880 sectors (RO), sector size=512

Partition table type (auto): Intel
Media is opened in read-only.
Partition table type (auto): Intel
Media is opened in read-only.
Disk /dev/disk2 - 2000 GB / 1863 GiB (RO)
Partition table type: Intel

Analyse Disk /dev/disk2 - 2000 GB / 1863 GiB - 3907028992 sectors (RO)
Geometry from i386 MBR: head=255 sector=63
FAT32 at 2048/0/1
Info: size boot_sector 3907026944, partition 3907026944
FAT1 : 32-476847
FAT2 : 476848-953663
start_rootdir : 953664 root cluster : 2
Data : 953664-3907026943
sectors : 3907026944
cluster_size : 64
no_of_cluster : 61032395 (2 - 61032396)
fat_length 476816 calculated 476816
heads/cylinder 255 (FAT) != 1 (HD)
sect/track 32 (FAT) != 1 (HD)
get_geometry_from_list_part_aux head=1 nbr=2
get_geometry_from_list_part_aux head=8 nbr=2
get_geometry_from_list_part_aux head=16 nbr=2
get_geometry_from_list_part_aux head=32 nbr=2
get_geometry_from_list_part_aux head=64 nbr=2
get_geometry_from_list_part_aux head=128 nbr=2
Current partition structure:
Warning: number of heads/cylinder mismatches 255 (FAT) != 1 (HD)
Warning: number of sectors per track mismatches 32 (FAT) != 1 (HD)
1 P FAT32 2048 3907028991 3907026944 [EW]

Warning: Bad starting sector (CHS and LBA don't match)
No partition is bootable

search_part()
Disk /dev/disk2 - 2000 GB / 1863 GiB - 3907028992 sectors (RO)
FAT32 at 2048/0/1
FAT1 : 32-476847
FAT2 : 476848-953663
start_rootdir : 953664 root cluster : 2
Data : 953664-3907026943
sectors : 3907026944
cluster_size : 64
no_of_cluster : 61032395 (2 - 61032396)
fat_length 476816 calculated 476816
heads/cylinder 255 (FAT) != 1 (HD)
sect/track 32 (FAT) != 1 (HD)

FAT32 at 2048/0/1
FAT: cluster=2(0x2), pos=955712
FAT32 LBA 2048 3907028991 3907026944 [EW]
FAT32, blocksize=32768, 2000 GB / 1863 GiB
get_geometry_from_list_part_aux head=1 nbr=2
get_geometry_from_list_part_aux head=8 nbr=2
get_geometry_from_list_part_aux head=16 nbr=2
get_geometry_from_list_part_aux head=32 nbr=2
get_geometry_from_list_part_aux head=64 nbr=2
get_geometry_from_list_part_aux head=128 nbr=2
Warning: the current number of heads per cylinder is 1 but the correct value may be 128.

Results
* FAT32 LBA 2048 3907028991 3907026944 [EW]
FAT32, blocksize=32768, 2000 GB / 1863 GiB

interface_write()
1 P FAT32 LBA 2048 3907028991 3907026944 [EW]

search_part()
Disk /dev/disk2 - 2000 GB / 1863 GiB - 3907028992 sectors (RO)
FAT32 at 2048/0/1
FAT1 : 32-476847
FAT2 : 476848-953663
start_rootdir : 953664 root cluster : 2
Data : 953664-3907026943
sectors : 3907026944
cluster_size : 64
no_of_cluster : 61032395 (2 - 61032396)
fat_length 476816 calculated 476816
heads/cylinder 255 (FAT) != 1 (HD)
sect/track 32 (FAT) != 1 (HD)

FAT32 at 2048/0/1
FAT: cluster=2(0x2), pos=955712
FAT32 LBA 2048 3907028991 3907026944 [EW]
FAT32, blocksize=32768, 2000 GB / 1863 GiB
FAT32 at 2054/0/1
FAT1 : 32-476847
FAT2 : 476848-953663
start_rootdir : 953664 root cluster : 2
Data : 953664-3907026943
sectors : 3907026944
cluster_size : 64
no_of_cluster : 61032395 (2 - 61032396)
fat_length 476816 calculated 476816
heads/cylinder 255 (FAT) != 1 (HD)
sect/track 32 (FAT) != 1 (HD)
set_FAT_info: name from BS used

FAT32 at 2054/0/1
FAT: cluster=2(0x2), pos=955712
FAT32 LBA 2048 3907028991 3907026944 [EW]
FAT32, blocksize=32768, 2000 GB / 1863 GiB
FAT32 at 2054/0/1
FAT1 : 32-476847
FAT2 : 476848-953663
start_rootdir : 953664 root cluster : 2
Data : 953664-3907026943
sectors : 3907026944
cluster_size : 64
no_of_cluster : 61032395 (2 - 61032396)
fat_length 476816 calculated 476816
heads/cylinder 255 (FAT) != 1 (HD)
sect/track 32 (FAT) != 1 (HD)
set_FAT_info: name from BS used

FAT32 at 2054/0/1
FAT: Directory entry is marked as free.
FAT: cluster=2(0x2), pos=955718
FAT32 LBA 2054 3907028997 3907026944 [EW]
FAT32, blocksize=32768, 2000 GB / 1863 GiB
This partition ends after the disk limits. (start=2054, size=3907026944, end=3907028997, disk end=3907028992)
Disk /dev/disk2 - 2000 GB / 1863 GiB - 3907028992 sectors (RO)
Check the hard disk size: HD jumper settings, BIOS detection...
The hard disk (2000 GB / 1863 GiB) seems too small! (< 2000 GB / 1863 GiB)
The following partition can't be recovered:
FAT32 LBA 2054 3907028997 3907026944 [EW]
FAT32, blocksize=32768, 2000 GB / 1863 GiB
get_geometry_from_list_part_aux head=1 nbr=2
get_geometry_from_list_part_aux head=8 nbr=2
get_geometry_from_list_part_aux head=16 nbr=2
get_geometry_from_list_part_aux head=32 nbr=2
get_geometry_from_list_part_aux head=64 nbr=2
get_geometry_from_list_part_aux head=128 nbr=2
Warning: the current number of heads per cylinder is 1 but the correct value may be 128.

Results
* FAT32 LBA 2048 3907028991 3907026944 [EW]
FAT32, blocksize=32768, 2000 GB / 1863 GiB
SIGHUP detected! PhotoRec has been killed.
SIGHUP detected! PhotoRec has been killed.
recuperation
Posts: 2801
Joined: 04 Jan 2019, 09:48
Location: Hannover, Deutschland (Germany, Allemagne)

Re: Recover MAC Partition from FAT32 Reformat

#2 Post by recuperation »

elcsum wrote: 21 Apr 2024, 23:42 I need help. I accidentally reformatted my 2TB Sandisk Extreme Portable SSD external. I believe I originally formatted the drive to MAC OS extended (journaled) and then selected the wrong drive and formatted the thing to FAT32. I have tried using TestDisk to recover with no luck and I think it may be in the settings I am using. I would appreciate any help. Here are me logs...
TestDisk would most probably find a "MAC OS extended" partition. It is able to find lots of file systems but is only capable to do some additional stuff like undeleting files or doing certain minimal defined repairs for instance.

By formatting you erased data within your "MAC OS extended" partition. There might be some data left after formatting your partition. You need something to examine the remains of your file system. You would need some commercial solution that understands the structure of your "MAC OS extended" partition instead of TestDisk. If everything else fails, use PhotoRec.
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