Recovery of a PVR fat32 Disk

How to use TestDisk to recover lost partition
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DeveloperChris
Posts: 3
Joined: 06 Aug 2012, 13:34

Recovery of a PVR fat32 Disk

#1 Post by DeveloperChris » 06 Aug 2012, 14:37

I have searched for the answer to this and so far have had no luck

Can testdisk use non standard sector and cluster sizes when searching a fat32 disk?

I have a corrupted 500GB western digital drive (it appears they have low tolerance to heat)

The drive is from a "beyonwiz" PVR
it uses a Cluster size of 512Kb
and a Sector size of 4096

It is recognised as a Fat32 LBA

Code: Select all

TestDisk 6.13, Data Recovery Utility, November 2011
Christophe GRENIER <grenier@cgsecurity.org>
http://www.cgsecurity.org

Disk /dev/sdc - 500 GB / 465 GiB - CHS 7601 255 63

     Partition                  Start        End    Size in sectors
> 1 P FAT32 LBA                0   1  1 60800 254 63  976768002
After setting the sector size to 4096 and then analysing I get this

Code: Select all

TestDisk 6.13, Data Recovery Utility, November 2011
Christophe GRENIER <grenier@cgsecurity.org>
http://www.cgsecurity.org

Disk /dev/sdc - 500 GB / 465 GiB - CHS 7601 255 63
Current partition structure:
     Partition                  Start        End    Size in sectors

Invalid FAT boot sector
 1 P FAT32 LBA                0   1  1 60800 254 63  976768002
 1 P FAT32 LBA                0   1  1 60800 254 63  976768002
No partition is bootable
After the analysis run (no to vista) No partition is found

Code: Select all

TestDisk 6.13, Data Recovery Utility, November 2011
Christophe GRENIER <grenier@cgsecurity.org>
http://www.cgsecurity.org

Disk /dev/sdc - 500 GB / 465 GiB - CHS 7601 255 63

     Partition                  Start        End    Size in sectors

No partition found or selected for recovery
What more can I do?

I am currently running fsck on a dd_rescue image of the disk but it is faltering on

Code: Select all

Bad short file name (�@&!@Q*\200.L4\227).
  Auto-renaming it.
  Renamed to FSCK0009.823
As you can see I am up to 9823 files. I am concerned its going to rename every file on the disk making it impossible for me to restore it

Any assistance would be greatly appreciated

DC

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Fiona
Posts: 2836
Joined: 18 Feb 2012, 17:19
Location: Ludwigsburg/Stuttgart - Germany

Re: Recovery of a PVR fat32 Disk

#2 Post by Fiona » 07 Aug 2012, 13:18

It's not possible that the cluster size is smaller than a sector?
Would it be possible to use TestDisk6.14WIP-32bit and confirm through until you see your disk selction.
Select your disk and confirm through until Analyse.
Please copy and paste the content of your testdisk.log in your testdisk folder.
The log file displays the sector size of your disk.
Video or HDD recorder often using Linux or UNIX file systems.
My one for example uses xfs file system.

Fiona

DeveloperChris
Posts: 3
Joined: 06 Aug 2012, 13:34

Re: Recovery of a PVR fat32 Disk

#3 Post by DeveloperChris » 08 Aug 2012, 00:08

Hi Fiona

Thankyou

The PVR uses fat32. The cluster size according to the beyonwiz forum is 512kB and the sector size is 4096 bytes beyond that I do not know much.

The linux kernel in the beyonwiz is an 2.4.x. but I do not know much about the differences between kernel revisions.

I am using knoppix livecd (7.02) to run testdisk as windows does not understand the fat format at all. as it does not recognise cluster sizes larger than 32kB so all the disk recovery tools I tried borked.

Code: Select all

DeveloperChris  

Wed Aug  8 07:03:54 2012
Command line: TestDisk

TestDisk 6.13, Data Recovery Utility, November 2011
Christophe GRENIER <grenier@cgsecurity.org>
http://www.cgsecurity.org
OS: Linux, kernel 3.4.4 (#14 SMP PREEMPT Sat Jun 23 20:07:21 CEST 2012) i686
Compiler: GCC 4.6
Compilation date: 2012-01-16T23:06:01
ext2fs lib: 1.42.4, ntfs lib: 10:0:0, reiserfs lib: none, ewf lib: none
/dev/sda: LBA, HPA, LBA48, DCO support
/dev/sda: size       488397168 sectors
/dev/sda: user_max   488397168 sectors
/dev/sda: native_max 488397168 sectors
/dev/sda: dco        488397168 sectors
/dev/sdb: LBA, HPA, LBA48, DCO support
/dev/sdb: size       976773168 sectors
/dev/sdb: user_max   976773168 sectors
/dev/sdb: native_max 976773168 sectors
/dev/sdb: dco        976773168 sectors
/dev/sdc: LBA, HPA, LBA48, DCO support
/dev/sdc: size       976773168 sectors
/dev/sdc: user_max   976773168 sectors
/dev/sdc: native_max 976773168 sectors
/dev/sdc: dco        976773168 sectors
Warning: can't get size for Disk /dev/mapper/control - 0 B - CHS 1 1 1, sector size=512
/dev/sr0 is not an ATA disk
Hard disk list
Disk /dev/sda - 250 GB / 232 GiB - CHS 30401 255 63, sector size=512 - ST3250823AS, S/N:4ND21DXT, FW:3.03
Disk /dev/sdb - 500 GB / 465 GiB - CHS 60801 255 63, sector size=512 - Hitachi HDS721050CLA362, S/N:JPB530HN3HBTVB, FW:JP2OA3EA
Disk /dev/sdc - 500 GB / 465 GiB - CHS 60801 255 63, sector size=512 - WDC WD5000AVJB-63J1A0, S/N:WD-WCASZ0989363, FW:05.04E05
Disk /dev/sdd - 888 GB / 827 GiB - CHS 107982 255 63, sector size=512 - Seagate FreeAgent Go, FW:0148
Disk /dev/sr0 - 726 MB / 692 MiB - CHS 354704 1 1 (RO), sector size=2048 - HL-DT-ST DVD-RW_GSA-H11N, S/N:04D84334797A, FW:JH02

Partition table type (auto): Intel
Disk /dev/sdc - 500 GB / 465 GiB - WDC WD5000AVJB-63J1A0
Partition table type: Intel

Analyse Disk /dev/sdc - 500 GB / 465 GiB - CHS 60801 255 63
Geometry from i386 MBR: head=255 sector=63
check_FAT: Incorrect number of bytes per sector 4096 (FAT) != 512 (HD)


test_FAT()
 1 P FAT32 LBA                0   1  1 60800 254 63  976768002
sector_size  4096
cluster_size 128
reserved     128
fats         2
dir_entries  0
sectors      0
media        F8
fat_length   0
secs_track   63
heads        255
hidden       0
total_sect   122096000
check_part_i386 failed for partition type 0C
get_geometry_from_list_part_aux head=255 nbr=2
get_geometry_from_list_part_aux head=8 nbr=1
get_geometry_from_list_part_aux head=16 nbr=1
get_geometry_from_list_part_aux head=32 nbr=1
get_geometry_from_list_part_aux head=64 nbr=1
get_geometry_from_list_part_aux head=128 nbr=1
get_geometry_from_list_part_aux head=240 nbr=1
get_geometry_from_list_part_aux head=255 nbr=2
Current partition structure:
check_FAT: Incorrect number of bytes per sector 4096 (FAT) != 512 (HD)
Invalid FAT boot sector
 1 P FAT32 LBA                0   1  1 60800 254 63  976768002
 1 P FAT32 LBA                0   1  1 60800 254 63  976768002
No partition is bootable
Ask the user for vista mode
Allow partial last cylinder : No
search_vista_part: 0

search_part()
Disk /dev/sdc - 500 GB / 465 GiB - CHS 60801 255 63
check_FAT: Incorrect number of bytes per sector 4096 (FAT) != 512 (HD)

Results

interface_write()
 
No partition found or selected for recovery
simulate write!

write_mbr_i386: starting...
write_all_log_i386: starting...
No extended partition

TestDisk exited normally.

DeveloperChris
Posts: 3
Joined: 06 Aug 2012, 13:34

Re: Recovery of a PVR fat32 Disk

#4 Post by DeveloperChris » 16 Aug 2012, 10:19

Bump

Any ideas what I can do?

User avatar
Fiona
Posts: 2836
Joined: 18 Feb 2012, 17:19
Location: Ludwigsburg/Stuttgart - Germany

Re: Recovery of a PVR fat32 Disk

#5 Post by Fiona » 17 Aug 2012, 08:15

FAT ist a Standard.
Sector size is usually 512 Bytes.
TestDisk recognizes your sector size as 512 Bytes only;
Disk /dev/sdc - 500 GB / 465 GiB - CHS 60801 255 63, sector size=512 - WDC WD5000AVJB-63J1A0,
If you're abolutely sure, you can use the menu geometry to increase your sector size.
4 KB sector size often reacts different.
If internally plugged in, 4 KB sector size disks won't boot.
The BIOS emulates your disk as 512 Byte sector size disk.
Some information about 4 K. sectors in this post also;
http://forum.cgsecurity.org/phpBB3/inco ... t1017.html

Until yet, you can resize your sector size using the menu geometry.
Please don't use the menu "Write" if your not 100 % sure.
So you can at least use it as a diagnose and it will help determine your status of your disk.
Also if you resize your sector size, please watch that message which TestDisk displays at the bottom of the display.

Please let me know, do you get different results?

Fiona

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