testdisk on a failed Linux md RAID10 member

[RobbieTheK]

I had a 4 disk Linux software RAID10 and 2 disks failed. I have access to the drives and testdisk does find and identify them correctly.

I've seen some folks have been able to recover a failed RAID member albeit on Windows viewtopic.php?t=824.

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Disk /dev/sdc - 2000 GB / 1863 GiB - ST2000DM001-1ER164

Please select the partition table type, press Enter when done.
>[Intel  ] Intel/PC partition

Hint: Intel partition table type has been detected.

Disk /dev/sdc - 2000 GB / 1863 GiB - CHS 243201 255 63
Current partition structure:
     Partition                  Start        End    Size in sectors

 1 P Linux RAID               0  32 33 243201  80 63 3907027120 [ourserver :2]
No partition is bootable

quick search:

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Disk /dev/sdc - 2000 GB / 1863 GiB - CHS 243201 255 63
     Partition               Start        End    Size in sectors
>* Linux RAID               0  32 33 243184 252 12 3906764800 [ourserver :2]

Structure: Ok.  Use Up/Down Arrow keys to select partition.
Use Left/Right Arrow keys to CHANGE partition characteristics:
*=Primary bootable  P=Primary  L=Logical  E=Extended  D=Deleted
Keys A: add partition, L: load backup, T: change type,
     Enter: to continue
md 1.x L.Endian Raid 10 - Array Slot : 2 (0, empty, 2), 2000 GB / 1862 GiB

Deep search start:

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Disk /dev/sdc - 2000 GB / 1863 GiB - CHS 243201 255 63
Analyse cylinder   536/243200: 00%

432 33 243184 219 51 3906762760 [ourserver :2]

Is deep search the best way to find any recoverable files?

[recuperation]

I do not have experience with your Linux raid configuration.
I just looked up what "RAID 10" stands for in a wikipedia article.

When the content is striped over two drives you cannot recover stuff by just applying Testdisk onto one single drive.
You have to make sure to have two drives in action that both represent all stripes involved.

When using Raid 0 one drive is perfectly OK to run Testdisk on one out of two because there is no striping involved. All data is on each disk it is mirrored.

In your case one disk only contains half of the stripes.
I guess you would have to apply Testdisk on that logical device that is dividing access into individual stripes on both drives.
Such a device should show a total size of 4000GB in your case.

That's why I did not answer your question.