implications of Geometry menu change of heads per cylinder

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Spark
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Joined: 06 Mar 2013, 02:38

implications of Geometry menu change of heads per cylinder

#1 Post by Spark » 06 Mar 2013, 03:10

Received
"Warning: the current number of heads per cylinder is 255 but the correct value may be 240.
You can use the Geometry menu to change this value.
It's something to try if
- some partitions are not found by TestDisk
- or the partition table can not be written because partitions overlaps."


If I change the Geometry does it risk losing possible recoverable data?


Or can I just change it and see if it helps recover and if not change it back with no impact?

Thank you!

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Fiona
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Re: implications of Geometry menu change of heads per cylind

#2 Post by Fiona » 06 Mar 2013, 08:08

In TestDisk you don't loose anything.
As long as you unsure, don't use the menu Write.
Geometry of 240 heads are often used by 2.5 inch disks in laptops/notebooks.
You should only change it, if a partition is not found or overlap with another one.
Microsoft changed partition alignment from Intel cylinder boundary to megabyte boundary.
In some cases you can get this message but it has no significance, because TestDisk works intel standard and microsoft is different.
In case, you can upload a screenshot from testdisk / anlyse or copy and paste the content of the testdisk.log.
So I could judge it.

Fiona

Spark
Posts: 6
Joined: 06 Mar 2013, 02:38

Re: implications of Geometry menu change of heads per cylind

#3 Post by Spark » 06 Mar 2013, 12:18

Log

Tue Mar 5 19:00:54 2013
Command line: TestDisk

TestDisk 6.14-WIP, Data Recovery Utility, March 2013
Christophe GRENIER <grenier@cgsecurity.org>
http://www.cgsecurity.org
OS: Windows XP SP3
Compiler: GCC 4.7, Cygwin 1007.17
Compilation date: 2013-03-02T11:22:18
ext2fs lib: 1.42.2, ntfs lib: 10:0:0, reiserfs lib: 0.3.1-rc8, ewf lib: 20120504
disk_get_size_win32 IOCTL_DISK_GET_LENGTH_INFO(/dev/sda)=160041885696
disk_get_size_win32 IOCTL_DISK_GET_LENGTH_INFO(/dev/sdb)=6007357440
disk_get_size_win32 IOCTL_DISK_GET_LENGTH_INFO(\\.\PhysicalDrive0)=160041885696
disk_get_size_win32 IOCTL_DISK_GET_LENGTH_INFO(\\.\PhysicalDrive1)=6007357440
disk_get_size_win32 IOCTL_DISK_GET_LENGTH_INFO(\\.\C:)=154799769600
disk_get_size_win32 IOCTL_DISK_GET_LENGTH_INFO(\\.\D:)=4567417344
disk_get_size_win32 IOCTL_DISK_GET_LENGTH_INFO(\\.\E:)=1439875584
Hard disk list
Disk /dev/sda - 160 GB / 149 GiB - CHS 19457 255 63, sector size=512 - ST916031 4AS, S/N:V61CF7G7, FW:0001
Disk /dev/sdb - 6007 MB / 5729 MiB - CHS 730 255 63, sector size=512 - TOSHIBA MK6014MAP, FW:0000

Partition table type (auto): Intel
Disk /dev/sdb - 6007 MB / 5729 MiB - TOSHIBA MK6014MAP
Partition table type: Intel

Analyse Disk /dev/sdb - 6007 MB / 5729 MiB - CHS 730 255 63
Geometry from i386 MBR: head=240 sector=63
FAT32 at 0/1/1
Info: size boot_sector 8920737, partition 8920737
FAT1 : 34-8728
FAT2 : 8729-17423
start_rootdir : 17424 root cluster : 2
Data : 17424-8920735
sectors : 8920737
cluster_size : 8
no_of_cluster : 1112914 (2 - 1112915)
fat_length 8695 calculated 8695
file_pread(5,16,buffer,97(0/1/35)) ReadFile Data error (cyclic redundancy check).

file_pread(5,1,buffer,97(0/1/35)) ReadFile Data error (cyclic redundancy check).

comp_FAT: can't read FAT1
heads/cylinder 240 (FAT) != 255 (HD)
set_FAT_info: name from BS used
BAD_RS LBA=8920800 9478350
BAD_RS LBA=8920863 9478413
FAT32 at 555/76/1
Info: size boot_sector 2812257, partition 2812257
FAT1 : 38-2778
FAT2 : 2779-5519
start_rootdir : 5520 root cluster : 2
Data : 5520-2812255
sectors : 2812257
cluster_size : 8
no_of_cluster : 350842 (2 - 350843)
fat_length 2741 calculated 2741
heads/cylinder 240 (FAT) != 255 (HD)
get_geometry_from_list_part_aux head=255 nbr=1
get_geometry_from_list_part_aux head=8 nbr=6
get_geometry_from_list_part_aux head=16 nbr=6
get_geometry_from_list_part_aux head=32 nbr=6
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=6
get_geometry_from_list_part_aux head=255 nbr=1
Current partition structure:
Warning: number of heads/cylinder mismatches 240 (FAT) != 255 (HD)
1 * FAT32 0 1 1 555 74 63 8920737 [NO NAME]

Bad sector count.
2 E extended LBA 555 75 1 730 89 63 2812320

Warning: Bad ending cylinder (CHS and LBA don't match)
Warning: number of heads/cylinder mismatches 240 (FAT) != 255 (HD)
5 L FAT32 555 76 1 730 89 63 2812257 [SYSTEM_SAVE]

Warning: Bad ending cylinder (CHS and LBA don't match)

search_part()
Disk /dev/sdb - 6007 MB / 5729 MiB - CHS 730 255 63
file_pread(5,16,buffer,95(0/1/33)) ReadFile Data error (cyclic redundancy check).

file_pread(5,1,buffer,97(0/1/35)) ReadFile Data error (cyclic redundancy check).

FAT32 at 0/1/1
FAT1 : 34-8728
FAT2 : 8729-17423
start_rootdir : 17424 root cluster : 2
Data : 17424-8920735
sectors : 8920737
cluster_size : 8
no_of_cluster : 1112914 (2 - 1112915)
fat_length 8695 calculated 8695
comp_FAT: can't read FAT1
heads/cylinder 240 (FAT) != 255 (HD)
set_FAT_info: name from BS used

FAT32 at 0/1/1
FAT32 0 1 1 555 74 63 8920737 [NO NAME]
FAT32, blocksize=4096, 4567 MB / 4355 MiB
BAD_RS LBA=8920863 9478413
heads/cylinder 240 (FAT) != 255 (HD)
FAT32 at 555/76/1
FAT1 : 38-2778
FAT2 : 2779-5519
start_rootdir : 5520 root cluster : 2
Data : 5520-2812255
sectors : 2812257
cluster_size : 8
no_of_cluster : 350842 (2 - 350843)
fat_length 2741 calculated 2741
heads/cylinder 240 (FAT) != 255 (HD)

FAT32 at 555/76/1
FAT32 555 76 1 730 89 63 2812257 [SYSTEM_SAVE]
FAT32, blocksize=4096, 1439 MB / 1373 MiB
file_pread(5,16,buffer,11733120(730/90/1)) ReadFile Data error (cyclic redundancy check).

file_pread(5,1,buffer,11733120(730/90/1)) ReadFile Data error (cyclic redundancy check).

file_pread(5,8,buffer,11733128(730/90/9)) lseek err Invalid argument
file_pread(5,3,buffer,11733136(730/90/17)) lseek err Invalid argument
file_pread(5,3,buffer,11733183(730/91/1)) lseek err Invalid argument
file_pread(5,8,buffer,11733199(730/91/17)) lseek err Invalid argument
file_pread(5,11,buffer,11733246(730/92/1)) lseek err Invalid argument
file_pread(5,2,buffer,11735168(730/122/33)) lseek err Invalid argument
get_geometry_from_list_part_aux head=255 nbr=1
get_geometry_from_list_part_aux head=8 nbr=4
get_geometry_from_list_part_aux head=16 nbr=4
get_geometry_from_list_part_aux head=32 nbr=4
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=4
get_geometry_from_list_part_aux head=255 nbr=1
Warning: the current number of heads per cylinder is 255 but the correct value may be 240.

Results
FAT32 0 1 1 555 254 63 8932077 [NO NAME]
FAT32, blocksize=4096, 4573 MB / 4361 MiB
FAT32 555 76 1 730 89 63 2812257 [SYSTEM_SAVE]
FAT32, blocksize=4096, 1439 MB / 1373 MiB

interface_write()

No partition found or selected for recovery

search_part()
Disk /dev/sdb - 6007 MB / 5729 MiB - CHS 730 255 63
file_pread(5,16,buffer,95(0/1/33)) ReadFile Data error (cyclic redundancy check).

file_pread(5,1,buffer,97(0/1/35)) ReadFile Data error (cyclic redundancy check).

FAT32 at 0/1/1
FAT1 : 34-8728
FAT2 : 8729-17423
start_rootdir : 17424 root cluster : 2
Data : 17424-8920735
sectors : 8920737
cluster_size : 8
no_of_cluster : 1112914 (2 - 1112915)
fat_length 8695 calculated 8695
comp_FAT: can't read FAT1
heads/cylinder 240 (FAT) != 255 (HD)
set_FAT_info: name from BS used

FAT32 at 0/1/1
FAT32 0 1 1 555 74 63 8920737 [NO NAME]
FAT32, blocksize=4096, 4567 MB / 4355 MiB
FAT32 at 0/1/7
FAT1 : 34-8728
FAT2 : 8729-17423
start_rootdir : 17424 root cluster : 2
Data : 17424-8920735
sectors : 8920737
cluster_size : 8
no_of_cluster : 1112914 (2 - 1112915)
fat_length 8695 calculated 8695
heads/cylinder 1 (FAT) != 255 (HD)
sect/track 49287 (FAT) != 63 (HD)
set_FAT_info: name from BS used

FAT32 at 0/1/7
FAT32 0 1 1 140 238 33 2264064
FAT found using backup sector!, 1159 MB / 1105 MiB
Search for partition aborted
get_geometry_from_list_part_aux head=255 nbr=2
get_geometry_from_list_part_aux head=8 nbr=3
get_geometry_from_list_part_aux head=16 nbr=3
get_geometry_from_list_part_aux head=32 nbr=3
get_geometry_from_list_part_aux head=64 nbr=2
get_geometry_from_list_part_aux head=128 nbr=2
get_geometry_from_list_part_aux head=240 nbr=3
get_geometry_from_list_part_aux head=255 nbr=2
Warning: the current number of heads per cylinder is 255 but the correct value may be 240.

Results
FAT32 0 1 1 140 254 63 2265102
FAT found using backup sector!, 1159 MB / 1106 MiB
FAT32 0 1 1 555 254 63 8932077 [NO NAME]
FAT32, blocksize=4096, 4573 MB / 4361 MiB

interface_write()

No partition found or selected for recovery
simulate write!

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

Analyse Disk /dev/sdb - 6007 MB / 5729 MiB - CHS 730 255 63
Geometry from i386 MBR: head=240 sector=63
FAT32 at 0/1/1
Info: size boot_sector 8920737, partition 8920737
FAT1 : 34-8728
FAT2 : 8729-17423
start_rootdir : 17424 root cluster : 2
Data : 17424-8920735
sectors : 8920737
cluster_size : 8
no_of_cluster : 1112914 (2 - 1112915)
fat_length 8695 calculated 8695
file_pread(5,16,buffer,97(0/1/35)) ReadFile Data error (cyclic redundancy check).

file_pread(5,1,buffer,97(0/1/35)) ReadFile Data error (cyclic redundancy check).

comp_FAT: can't read FAT1
heads/cylinder 240 (FAT) != 255 (HD)
set_FAT_info: name from BS used
BAD_RS LBA=8920800 9478350
BAD_RS LBA=8920863 9478413
FAT32 at 555/76/1
Info: size boot_sector 2812257, partition 2812257
FAT1 : 38-2778
FAT2 : 2779-5519
start_rootdir : 5520 root cluster : 2
Data : 5520-2812255
sectors : 2812257
cluster_size : 8
no_of_cluster : 350842 (2 - 350843)
fat_length 2741 calculated 2741
heads/cylinder 240 (FAT) != 255 (HD)
get_geometry_from_list_part_aux head=255 nbr=1
get_geometry_from_list_part_aux head=8 nbr=6
get_geometry_from_list_part_aux head=16 nbr=6
get_geometry_from_list_part_aux head=32 nbr=6
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=6
get_geometry_from_list_part_aux head=255 nbr=1
Current partition structure:
Warning: number of heads/cylinder mismatches 240 (FAT) != 255 (HD)
1 * FAT32 0 1 1 555 74 63 8920737 [NO NAME]

Bad sector count.
2 E extended LBA 555 75 1 730 89 63 2812320

Warning: Bad ending cylinder (CHS and LBA don't match)
Warning: number of heads/cylinder mismatches 240 (FAT) != 255 (HD)
5 L FAT32 555 76 1 730 89 63 2812257 [SYSTEM_SAVE]

Warning: Bad ending cylinder (CHS and LBA don't match)

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cgrenier
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Re: implications of Geometry menu change of heads per cylind

#4 Post by cgrenier » 11 Mar 2013, 17:54

The CRC errors are due to bad sectors. You should clone your disk to a new empty one as described in
http://www.cgsecurity.org/wiki/Damaged_Hard_Disk
Once the copy is done, remove the original disk and try to recover your data from the clone.

Spark
Posts: 6
Joined: 06 Mar 2013, 02:38

Re: implications of Geometry menu change of heads per cylind

#5 Post by Spark » 11 Mar 2013, 22:37

Recommendation on method or recovery from the clone? Such as change geometry menu 255 to 240?

Thank you!

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cgrenier
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Joined: 18 Feb 2012, 15:08
Location: Le Perreux Sur Marne, France
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Re: implications of Geometry menu change of heads per cylind

#6 Post by cgrenier » 26 Mar 2013, 08:40

On the clone, try to list and copy your files using TestDisk, Advanced, Boot, List

Spark
Posts: 6
Joined: 06 Mar 2013, 02:38

Re: implications of Geometry menu change of heads per cylind

#7 Post by Spark » 03 Apr 2013, 23:36

Disk read errors on attempt to clone using both Macrium and Paragon. If I can't duplicate the drive image should I go forth with changing the geometry or will that risk the data that might be recoverable and best to try another alternative?

Thank you for advice!

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