cgsecurity.org

Posted: **05 Oct 2019, 10:40**

I recently noticed that my SD card that camera is using has some partition problem. I'm not sure why but I suppose I removed it to early when writing process take place. Now I have a problem because I have really important video from car accident and I don't have this data.

Now on my OSX I see the message:

"The disk you inserted was not readable by this computer"

I'm trying to learn how to fix this partition using testdisk. I'm not sure what kind of partition it was at all? Was it FAT or NTFS or something else?

I downloaded whole sd card to disk using:

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sudo ddrescue /dev/disk2 ~/tomek.dd ~/tomek.log

Then I ran:

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sudo ./testdisk ~/tomek.dd

I'm not sure what should I select on the following screen:

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TestDisk 7.2-WIP, Data Recovery Utility, July 2019
Christophe GRENIER <grenier@cgsecurity.org>
https://www.cgsecurity.org


Disk /Users/kapucha/tomek.dd - 32 GB / 30 GiB

Please select the partition table type, press Enter when done.
 [Intel  ] Intel/PC partition
>[EFI GPT] EFI GPT partition map (Mac i386, some x86_64...)
 [Humax  ] Humax partition table
 [Mac    ] Apple partition map (legacy)
 [None   ] Non partitioned media
 [Sun    ] Sun Solaris partition
 [XBox   ] XBox partition
 [Return ] Return to disk selection




Note: Do NOT select 'None' for media with only a single partition. It's very
rare for a disk to be 'Non-partitioned'.

I tried many option but I'm not sure if I made it right. What if I replaced old partition table with new one? Is there any way to recover the old partition table if new is written?

Should I setup some additional disk geometry settings if I copied this sd card to my local ssd disk? I'm asking because there is a note in app:

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Note: Correct disk geometry is required for a successful recovery. 'Analyse'
process may give some warnings if it thinks the logical geometry is mismatched.

When I select: EFI GPT -> Analyse I see this information:

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Disk /Users/kapucha/tomek.dd - 32 GB / 30 GiB - CHS 3917 255 63
Current partition structure:
     Partition                  Start        End    Size in sectors

Bad GPT partition, invalid signature.
Trying alternate GPT
Bad GPT partition, invalid signature.

When I select: Intel -> Analyse I see this information:

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Disk /Users/kapucha/tomek.dd - 32 GB / 30 GiB - CHS 3917 255 63
Current partition structure:
     Partition                  Start        End    Size in sectors


Partition sector doesn't have the endmark 0xAA55

Quick Search in both cases are not finding any partitions.

Posted: **06 Oct 2019, 08:14**

So far all SD card over 1 GB I have seen are using PC Intel partition table, not EFI GPT.
As TestDisk hasn't found your partition, try PhotoRec to recover your lost data.

cgsecurity.org

Recovering partition in SD disk from car camera

Recovering partition in SD disk from car camera

Re: Recovering partition in SD disk from car camera