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Hello. I recently screwed up a hard drive which I was using for data storage on my Ubuntu system, and now can not see anything that I had stored there. This 2TB drive had been configured just for storage with a single ext4 partition , and had about 1.2TB free, so I thought I could squeeze in a partition of about 1TB, where I wanted to install Mythbuntu. During the Mythbuntu install I was given the option to resize the drive's partition ( I thought ) and I screwed something up while doing that. Now I only see a 1TB partition with the new OS files, and I lost the 800GB of stored data. I was hoping that Testdisk could help but I am having problems, due to my limited understanding of partitions and Testdisk. I have tried my best but can't seem to get anywhere. Can I get back to nmy data using Testdisk, or should I go over to Photrec?

Seems like forum rules do not allow me to attach my testdisk.log here , so I cut/paste the results after "Analyse":

TestDisk 7.1, Data Recovery Utility, July 2019
Christophe GRENIER <grenier@cgsecurity.org>
https://www.cgsecurity.org

Disk /dev/sdb - 2000 GB / 1863 GiB - CHS 243201 255 63
Partition Start End Size in sectors
P EFI System 40 409639 409600 [EFI System Partition] [EFI]
>P Linux filesys. data 1953904640 3907029127 1953124488

Structure: Ok. Use Up/Down Arrow keys to select partition.
Use Left/Right Arrow keys to CHANGE partition characteristics:
P=Primary D=Deleted
Keys A: add partition, L: load backup, T: change type, P: list files,
Enter: to continue
ext4 blocksize=4096 Large_file Sparse_SB, 999 GB / 931 GiB

At the start of the search, "Deeper Search" shows :

check_FAT: Unusual media descriptor (0xf0!=0xf8)
Warning: number of heads/cylinder mismatches 16 (FAT) != 255 (HD)
Warning: number of sectors per track mismatches 32 (FAT) != 63 (HD)
EFI System 40 409639 409600 [EFI System Partition] [EFI]
check_FAT: Unusual media descriptor (0xf0!=0xf8)
Warning: number of heads/cylinder mismatches 16 (FAT) != 255 (HD)
Warning: number of sectors per track mismatches 32 (FAT) != 63 (HD)
EFI System 46 409645 409600 [EFI System Partition] [EFI]

.and then upon completion of "Deeper Search" , displays:

..TestDisk 7.1, Data Recovery Utility, July 2019
Christophe GRENIER <grenier@cgsecurity.org>
https://www.cgsecurity.org

Disk /dev/sdb - 2000 GB / 1863 GiB - CHS 243201 255 63

The harddisk (2000 GB / 1863 GiB) seems too small! (< 4000 GB / 3725 GiB)
Check the harddisk size: HD jumper settings, BIOS detection...

The following partitions can't be recovered:
Partition Start End Size in sectors
> Linux filesys. data 2926458910 4879583397 1953124488
Linux filesys. data 2926458912 4879583399 1953124488
Linux filesys. data 2926983190 4880107677 1953124488
Linux filesys. data 2926983192 4880107679 1953124488
Linux filesys. data 2927245328 4880369815 1953124488
Linux filesys. data 2927246432 4880370919 1953124488
Linux filesys. data 2927246568 4880371055 1953124488
Linux filesys. data 2927246688 4880371175 1953124488
Linux filesys. data 2927246752 4880371239 1953124488
Linux filesys. data 2927246816 4880371303 1953124488

[ Continue ]
ext4 blocksize=4096 Large_file Sparse_SB Backup_SB, 999 GB / 931 GiB


The list of partitions which can't be recovered scrolls on forever-- I can't tell you how long this list is, but there are a number of Mac HFS partiotions that come up last on the list ( this hard drive saw a previous life in a Mac:
The following partitions can't be recovered:
Partition Start End Size in sectors
> Linux filesys. data 2927507280 4880631767 1953124488
Linux filesys. data 2927507416 4880631903 1953124488
Mac HFS 3038180068 6039618840 3001438773
Mac HFS 3841755268 4051470467 209715200
Mac HFS 3905759588 7811109539 3905349952
Mac HFS 3905770677 3907040212 1269536
Mac HFS 3905770877 3907040412 1269536
Mac HFS 3905771157 3907040692 1269536
Mac HFS 3905771437 3907040972 1269536
Mac HFS 3905771580 3907041115 1269536

I can use any suggestions as to my next step. My preference is to try and get the partition issue resolved, although I know I can get the data back (mostly images were stored here ) using PhotoRec.

Thank you for any suggestions. If there is a way to upload the testdisk.log file, please let me know how I can do this.

--Peter

Hi--Sorry-- here is a little more information from Testdisk, found at the end of the long list of partions from Deeper Search:


Disk /dev/sdb - 2000 GB / 1863 GiB - CHS 243201 255 63
Partition Start End Size in sectors
>D EFI System 40 409639 409600 [EFI System Partition] [EFI]
D EFI System 46 409645 409600 [EFI System Partition] [EFI]
D Mac HFS 409640 3905759591 3905349952
D Mac HFS 409640 3906766983 3906357344
D Mac HFS 36741299 3038180071 3001438773
D Mac HFS 1290413416 2104116074 813702659
D Linux filesys. data 1953904638 3907029125 1953124488
D Linux filesys. data 1953904640 3907029127 1953124488
D MS Data 1963396155 1963399034 2880 [NO NAME]
D MS Data 1963396179 1963399058 2880 [NO NAME]
D MS Data 1963397027 1963399906 2880 [NO NAME]
D Linux filesys. data 1963760421 1972129127 8368707 [1M-@ ~?~?^O^_~@]
D Linux filesys. data 1963760422 1972129128 8368707 [1M-@ ~?~?^O^_~@]
D Mac HFS 2002109628 2002629739 520112
D Mac HFS 2002619580 2002631787 12208
D Mac HFS 2002629736 2003149847 520112
D Mac HFS 2002631784 2002643991 12208
D Mac HFS 2002631788 2002643995 12208
D Mac HFS 2002635692 2002647899 12208
D Mac HFS 2002643992 2002656199 12208
D Mac HFS 2002647896 2002660103 12208
D Mac HFS 2002647900 2002660107 12208
D Mac HFS 2002650268 2002662475 12208
D Mac HFS 2002660104 2002672311 12208
D Mac HFS 2002662472 2002674679 12208
Structure: Ok. Use Up/Down Arrow keys to select partition.
Use Left/Right Arrow keys to CHANGE partition characteristics:
P=Primary D=Deleted
Keys A: add partition, L: load backup, T: change type, P: list files,
Enter: to continue
FAT32, blocksize=512, 209 MB / 200 MiB

palopez123 wrote: 03 Sep 2025, 05:37 Hello. I recently screwed up a hard drive which I was using for data storage on my Ubuntu system, and now can not see anything that I had stored there. This 2TB drive had been configured just for storage with a single ext4 partition , and had about 1.2TB free, so I thought I could squeeze in a partition of about 1TB, where I wanted to install Mythbuntu. During the Mythbuntu install I was given the option to resize the drive's partition ( I thought ) and I screwed something up while doing that. Now I only see a 1TB partition with the new OS files, and I lost the 800GB of stored data. I was hoping that Testdisk could help but I am having problems, due to my limited understanding of partitions and Testdisk. I have tried my best but can't seem to get anywhere. Can I get back to nmy data using Testdisk, or should I go over to Photrec?

Please do not use an outdated version of TestDisk. You can always use Photorec but you would be loosing the folder structure and file name information. Fragmentation would diminish the recovery process even further.

Unfortunately you did not report if and where you might have interrupted the installation process by just saying "I screwed something up".

As for your current big linux partition it seems to start in the middle of the disk:

>P Linux filesys. data 1953904640 3907029127 1953124488

Most parts of the content of your ext4 partition might still be available in the area below sector 1953904640.
I am not familiar with ext4 recovery, but maybe using the recipe in the TestDisk manual file testdisk.pdf

https://www.cgsecurity.org/testdisk_doc ... superblock

might give better recovery results.

As that procedure also involves running a file system check which modifies your logically broken disk, you should clone the disk using ddrescue as described in the manual so that you have a unmodified disk basis for maybe running PhotoRec later.

I can use any suggestions as to my next step. My preference is to try and get the partition issue resolved, although I know I can get the data back (mostly images were stored here ) using PhotoRec.

I am always surprised about forum members who have a crystal ball.

Thank you for any suggestions. If there is a way to upload the testdisk.log file, please let me know how I can do this.

I guess that you can do that now.

Thank you recuperation for your informative reply.

Thank you for any suggestions. If there is a way to upload the testdisk.log file, please let me know how I can do this.

I see now that I can post my testdisk log, which I have enclosed in a zipped format to keep file size below the 512KB.

[Please do not use an outdated version of TestDisk./quote]
I am having trouble moving to Testdisk7.2 but will look elsewhere on this site to see why I am having trouble,

nfortunately you did not report if and where you might have interrupted the installation process by just saying "I screwed something up".

Haha--that's my way of saying that I must have done something wrong, which is always my assumption when things don't work. There was no interruption in the installation, although I can note that the new OS was not added to other OSs already listed in GRUB. Can't recall any issue during the Mythbuntu install.

Most parts of the content of your ext4 partition might still be available in the area below sector 1953904640.

This is great news!

[I am not familiar with ext4 recovery, but maybe using the recipe in the TestDisk manual file testdisk.pdf/quote]
I will have a look and follow the recipe as you advised.

As that procedure also involves running a file system check which modifies your logically broken disk, you should clone the disk using ddrescue

Great advice. I need to find that 8TB disk I packed before I moved and get it unpacked and nto my computer box do I can make the copy,

I am always surprised about forum members who have a crystal ball.

Haha-- I am speaking from experience here, since I've had past issues where PhotoRec rescued the pictures I needed--usually as a result of a camera/computer issue during transfer of images from camera to computer.

Thanks again for all the comments and I'll report back with a progress update

--Peter

I don't find additional useful information in your log file.
The superblocks that were found belong to the partition in the second half of your disk. Nothing points to the first half of your disk where your data should be.

Try out other recovery software that support ext4.
If that does not help either, run PhotoRec.