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Hi all of you,

i have problems with my Samsung evo 860 500Gb ssd. I use it with win10 on an older machine that was a pain to get running with some old drivers.

- got "No operation system found" when i tried booting
- plugging it in my pc (win10) i'm asked to format the drive
- chkdsk and crystal disc ask to format the drive
- properties -> filesystem has no entry
- windows disk managament finds 3 partitions
readings below sizes are: no errors (active, primary partition) - no errors (recovery partition) - not allocated
- starting Testdisk [create] - [500gb samsung] - [efi GPT] - [analyze]
and this shows up:

- running [quicksearch] jumps to immediately 64%
- 80 minutes later it is done giving me:

(I ran the quicksearch before and it stuck on 99% once)
- [continue] leads to:

readings from top to bottom are: Now this is where i don't know what to do, examples and other cases didn't give me a clue. The interlaced sectors of the partitions seem confusing, although i would like to fiddle around on my own I never did this and don't want to loose the data. For some time i thought i'd had to repair the mbr but wouldn't it show the partitions in windows if that's the case?

Thank you for your thoughts and replys!

The alternate GPT looks good.
I can't find the sector size of your Samsung evo 860 500GB, I assume it is 512 bytes (emulated). I think the log file would tell.
Multiply the number of sectors of each partition by 512 to get its total size in bytes.

Did you only use 250GB for the latest partition leaving approx 250GB unused (for overprovisioning)?

I have never installed Windows 10 and do not have experience with your configuration!

This is what I would do:
Use the backup function on your first screen to write the partition structure of your alternate GPT onto a safe location (not your Samsung SSD!).
After quicksearch use the L-key ("load backup") to reload the alternate GPT. Use the P-key ("list files") to check if the content of the partitions as described by the alternate GPT meet your expectations. Then you would continue and write that GPT structure.

You can connect the drive to a Windows machine afterwards and check if the partitions are accesible.
If it does not boot I would use some Windows 10 recovery media for repair as I don't know today's tools and tricks for it.

If in doubt about data loss, duplicate the drive using ddrescue p.e..

floatingBombay wrote: 25 Oct 2020, 19:53 The interlaced sectors of the partitions seem confusing,

They are not allowed to be interlaced. Das gäbe Gehacktes.

although i would like to fiddle around on my own I never did this and don't want to loose the data.

Use a backup for fiddling around.

For some time i thought i'd had to repair the mbr but wouldn't it show the partitions in windows if that's the case?

There is a MBR but it has only the purpose to signal to old software that are not aware of GPTs that your disc is in use.

Have you noticed that there is a German section in the forum? Hätte mir das Leben leichter gemacht.

Thanks you, first i create a backup using r-studio. Does it matter that it is a compressed img?

Did you only use 250GB for the latest partition leaving approx 250GB unused (for overprovisioning)?

That is possible though i don't quite remember.

This is what I would do:

As soon as the backup has finished i will do that!


Ja, habe ich. Allerdings dachte ich, dass der Beitrag im englischen öfter gelesen wird . Kann ich also hier auf deutsch fortfahren?
Ich kann den Inhalt der "testdisk.log" hier nicht posten weil er über 60k zeichen enthält.

Will update soonish!

Hello again

Use the backup function on your first screen to write the partition structure of your alternate GPT onto a safe location (not your Samsung SSD!).
After quicksearch use the L-key ("load backup") to reload the alternate GPT. Use the P-key ("list files") to check if the content of the partitions as described by the alternate GPT meet your expectations. Then you would continue and write that GPT structure.

So after i reload the GPT i get this


That selected partition seems to be my suspect because the size fits that 250Gb but i don't have the option to list files there, so what can i do form here?
Another question i have is what my expectations roughly are, maybe i will know once i can "list files"?

Edit1: On the screenshot above, if i select the third entry and press P to "list files" testdisk just gets shutdown. I consider that a dire sign.