TestDisk with single-partitioned FAT32 1TB USB HDD

How to use TestDisk to recover lost partition
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Author
anbelo
Posts: 8
Joined: 25 Jun 2012, 09:28

TestDisk with single-partitioned FAT32 1TB USB HDD

#1 Post by anbelo »

Hello,

I'm running TestDisk from Linux on a single-partitioned FAT32 1TB USB HDD which I used to share data between Linux, Windows and Mac. Now it's not mounting on any system.

Test Disk detected the original partition as duplicated:

Current partition structure:
Bad MAC partition, invalid block0 signature
1 P partition_map 1 63 63
2 P DOS_FAT_32 64 1953525151 1953525088
2 P DOS_FAT_32 64 1953525151 1953525088
3 P Free 1953525152 1953525167 16


And after performing a Quick Search (which took about 10 hours), it found the following:

P Linux 1061356992 1064555623 3198632 [Ò2¹±¯î³€‡º]]

which I understand to be a new Linux partition, that is causing the problem.

Now I'm performing a Deep Search, that I hope will find the original FAT partition (after some other 10 hours).

Could you please tell me how to proceed when the Deep Search ends, should I mark the new Linux partiton as D (Deleted)? I upload the full log file.

Thank you very much in advance.
Attachments
testdisk.log.zip
Log file before Deep Search.
(1.24 KiB) Downloaded 422 times

User avatar
Fiona
Posts: 2835
Joined: 18 Feb 2012, 17:19
Location: Ludwigsburg/Stuttgart - Germany

Re: TestDisk with single-partitioned FAT32 1TB USB HDD

#2 Post by Fiona »

Do you have a Power PC or Intel Mac?

That partition is not duplicated bot it's normally a message that your boot sector might be invalid.
Can you have a boot sector diagnose like in this case?
http://forum.cgsecurity.org/phpBB3/part ... h-t14.html

Fiona

anbelo
Posts: 8
Joined: 25 Jun 2012, 09:28

Re: TestDisk with single-partitioned FAT32 1TB USB HDD

#3 Post by anbelo »

Hi Fiona, and thank you for your quick response.

I have an Intel Mac, which I used to create the FAT32 partition.

I have proceeded with the boot diagnose, and this is the result:

Disk /dev/sdb - 1000 GB / 931 GiB - CHS 121601 255 63
Partition Start End Size in sectors
2 P DOS_FAT_32 64 1953525151 1953525088

FAT : 32
cluster_size 128 0
reserved 31 0
total_sect 1953522309 0
fat32_length 119219 0
root_cluster 2 0
free_count uninitialised 0
next_free uninitialised 0
Extrapolated boot sector and current boot sector are different.


If I enter the "List" option, I can see my data.

Should I then press "q" to go back to the previous screen, and then "Write" to write the boot? Thanks again.

anbelo
Posts: 8
Joined: 25 Jun 2012, 09:28

Re: TestDisk with single-partitioned FAT32 1TB USB HDD

#4 Post by anbelo »

I have proceeded as in http://www.cgsecurity.org/wiki/Advanced ... oot_sector, writing the boot sector after checking I could see the data.

Now everything looks good (I attach the log file), and the USB disk seems to work fine with my Mac :) but it still doesn't mount on my Linux :(
Attachments
testdisk.log.zip
Log file after rebuilding/writing boot and re-analysing.
(11.41 KiB) Downloaded 389 times

User avatar
Fiona
Posts: 2835
Joined: 18 Feb 2012, 17:19
Location: Ludwigsburg/Stuttgart - Germany

Re: TestDisk with single-partitioned FAT32 1TB USB HDD

#5 Post by Fiona »

Your current partition structur or partition table (is the same) displays a bad MAC partition.
Do you need that partition?
It's an old standard of partition map supported on Power MAC.
Intel Macs have EFI GPT.
Please let me know do you have a Power PC or an Intel Mac
Current partition structure:
Bad MAC partition, invalid block0 signature
1 P partition_map 1 63 63
2 P DOS_FAT_32 64 1953525151 1953525088
2 P DOS_FAT_32 64 1953525151 1953525088
3 P Free 1953525152 1953525167 16
Might be worth to have a try to rewrite your partition table.
Partition table type Intel might be an idea.
Linux would probaly able to mount it correctly?
I'm not as much a Linux or Apple tech savvy, but in any case it's worth a try.
Please let me know, do you what kind of Apple computer you have (Intel or Power PC)
If you don't need your partition map-partition you could probably delete it.

Fiona

anbelo
Posts: 8
Joined: 25 Jun 2012, 09:28

Re: TestDisk with single-partitioned FAT32 1TB USB HDD

#6 Post by anbelo »

I have an Intel Mac. How should I proceed then?

User avatar
Fiona
Posts: 2835
Joined: 18 Feb 2012, 17:19
Location: Ludwigsburg/Stuttgart - Germany

Re: TestDisk with single-partitioned FAT32 1TB USB HDD

#7 Post by Fiona »

Do you have any idea about that primary Free partition?
There is no partition type nor file system.
If you don't need that free partition?
Partition tabel type is only 1 sector or 512 Bytes.
Your current partition table should look like that;
1 P partition_map 1 63 63
2 P DOS_FAT_32 64 1953525151 1953525088
3 P Free 1953525152 1953525167 16
To have a try to make it mountable under Linux you can test to write an intel partition table.
If you come to the partition table types in TestDisk please choose partition table type intel.
As far as I know it's compatible to Mac and Linux.
In Quick Search when your partitions are listed green, you can mark the first partition and use your left or right arrow key to set it to D for deleted.
Leave the rest like it is.
Prss entger to proceed.
Mark Write and press enter and y to confirm.
Now you should have an intel partition.
Have another try to mount it using Linux and check it using Apple also.

Please let me know.

anbelo
Posts: 8
Joined: 25 Jun 2012, 09:28

Re: TestDisk with single-partitioned FAT32 1TB USB HDD

#8 Post by anbelo »

When I select Intel partition table and go into Quick Search, this is what I get:

Code: Select all

Disk /dev/sdb - 1000 GB / 931 GiB - CHS 121601 255 63

     Partition                  Start        End    Size in sectors

 1 * FAT32 LBA                0   1  1 121600 254 63 1953520002 [LACIE]
Should I press "Write", or go into "Deeper Search"?

(And just to be sure: the partition I must delete is "3 P Free 1953525152 1953525167 16", isn't it? Thank you!).

User avatar
Fiona
Posts: 2835
Joined: 18 Feb 2012, 17:19
Location: Ludwigsburg/Stuttgart - Germany

Re: TestDisk with single-partitioned FAT32 1TB USB HDD

#9 Post by Fiona »

You don't need Deeper Search.
Easily use write and let me know the results.
Are you able to use it under Apple and Linux?

Fiona

anbelo
Posts: 8
Joined: 25 Jun 2012, 09:28

Re: TestDisk with single-partitioned FAT32 1TB USB HDD

#10 Post by anbelo »

I'm afraid it doesn't work yet :(

This is what appears now when I enter TestDisk:

Code: Select all

Disk /dev/sdb - 1000 GB / 931 GiB - CHS 121601 255 63
Current partition structure:
     Partition                  Start        End    Size in sectors

 1 * FAT32 LBA                0   1  1 121600 254 63 1953520002 [LACIE]

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