Welcome, Guest. Please login or register.
Did you miss your activation email?
June 20, 2019, 07:34:48 AM
Home Help Search Login Register
News:

+  DIY DataRecovery.nl Support forum
|-+  Support
| |-+  DiskPatch (Moderators: Tom, Joep)
| | |-+  Please add customization to multi-pass cloning
0 Members and 1 Guest are viewing this topic. « previous next »
Pages: [1] Go Down Print
Author Topic: Please add customization to multi-pass cloning  (Read 7564 times)
donalddavid
member

Posts: 7


« on: November 23, 2013, 01:35:13 AM »

Hi there,
I have been using DiskPatch for a while and I think it is a brilliant software with great potential, and I truly love the 2 pass cloning option within it, but the problem is that different scenarios needs different pass values, we should be able to customize the multi-pass option, we want more than 2 pass imaging, we want 5 pass imaging.
I would like to be able to customize number of passes and the Timeouts.

Timeout: length of pause after error encountered
Sector Skip: length of forward jump after read error or timeout encountered

Here are different scenarios for cloning the drive:

2 pass (few or no defects): Works best for hard drives that do not have many uncorrectable (bad) sectors.
Pass #1
Timeout: 20 seconds
Sector Skip: 1,000,000 sectors
Pass #2
Timeout: 60 seconds
Sector Skip: 0 sectors (no skip)

2 pass (micro timeouts): Works best for certain hard drive models (for example IBM and Hitachi) with many bad sectors.
Pass #1
Timeout:8 seconds
Sector Skip:1,000,000 sectors
Pass #2
Timeout: 2 seconds
Sector Skip:0 sectors (no skip)

3 pass (moderate damage): Extracts data quickly in first pass, and then slows down on subsequent passes to optimize data extraction.
Pass #1
Timeout: 20 seconds
Sector Skip: 1,000,000 sectors
Pass #2
Timeout: 20 seconds
Sector Skip: 100,000 sectors
Pass #3
Timeout: 60 seconds
Sector Skip: 0 sectors (no skip)

5 pass (unstable disk): Extracts data quickly in first pass, and then slows down on subsequent passes to optimize data extraction.
Pass #1
Timeout:20 seconds
 Sector Skip: 1,000,000 sectors
Pass #2
Timeout: 20 seconds
Sector Skip:100,000 sectors
Pass #3
Timeout:20 seconds
 Sector Skip: 10,000 sectors
Pass #4
Timeout:20 seconds
 Sector Skip: 1,000 sectors
Pass #5
Timeout:60 seconds
 Sector Skip:0 sectors (no skip)

 



Logged
Tom
Developer and Support Tech
Administrator
member
*****
Posts: 1476


WWW
« Reply #1 on: November 23, 2013, 08:05:43 PM »

The current 2-step clone process doesn't allow that sort of customization, from a code point of view. The two steps are connected, they "talk to one another" so to speak.
I think I get what you want though. It would be almost like a script for a clone operation; select the number of passes, tweak each pass, then start the whole process. That is an interesting thought, and we will look into that.
Logged

donalddavid
member

Posts: 7


« Reply #2 on: November 24, 2013, 10:26:44 AM »

Thanks for your reply!  Smiley

DiskPatch is one out of few softwares that have the ability of multipass imaging, and this feature is considered extremely effective and efficient when dealing with cases with severely damaged and corrupted  drives.Thus the need of extending passes and customization urge.
Logged
Tom
Developer and Support Tech
Administrator
member
*****
Posts: 1476


WWW
« Reply #3 on: November 24, 2013, 03:16:43 PM »

Just curious here. Do you have any experiences that indicate the need for what you describe above? Have you seen clone results improve when (manually) doing what you explained?
Logged

donalddavid
member

Posts: 7


« Reply #4 on: November 25, 2013, 09:06:18 PM »

Thanks again for replying and for seriously considering my suggestions.

Imaging a healthy Drive is very simple and straightforward, there are thousands of programs that offer delivering that task effectively and for free!  The problem is when dealing with damaged and unstable disks, attempts to read the drive are extremely slow and could take days to read the sectors on such a drive.
Hard drives with bad sectors require a complex imaging approach:
First: Try to extract as much data as possible and quickly in the first pass with implementing timeouts of 20 seconds and big sector skip jumps when encountering a bad sector.
Secondly: Repeat the same imaging task while keeping the same 20 second timeouts and decrease the sector skip by " dividing it by 10" in each imaging pass till it reaches 1,000 sector jumps.
Finally: At the last imaging pass increase the timeouts to the maximum of 60 seconds and no sector skip with 0 jumps.
(Manually)
Skipping sectors in the first pass save a considerable period of time by imaging the good areas of the drive first and guarantee that the disk will not be stressed any more than necessary, though the skipped sectors may contain important data, the subsequent passes assure the maximum scale of data recovery and approach the bad areas of the disk gradually.
This technique will even allow imaging of the disk drive in a way that the failing "HDD head" can be ignored for the disks with single head failure.
Badly damaged disks may take a long time at the last imaging pass, but it will give results and I think it's worth it.

Take this situation for example:
A drive with 70% of data with no errors, 14% of data are mixed with medium level of bad sectors, and the rest 16% are mixed with stubborn high level of bad sectors.
The 2-pass imaging will recover the 70% in the first pass + 7% from the medium level bad sectors in the second pass + 0% non from the stubborn bad areas of the disk, which leaves 23% of data unrecovered! that is really a big amount of data unrecovered!
Add an option to skip bad sectors and save their location in a log file so that the subsequent passes automatically skip them, for example:
In the first pass 10,000 bad sectors found and are saved in the bad sector log file.
In the second pass  the bad sectors found in the first pass are automatically skipped, and if new bad sectors are found they are added to the log file too.
The third and fourth pass the same thing.
But in the final pass the bad sectors that are saved in the "bad sectors log file" are targeted and the program tries to read them and extract data from them.

Conclusion:
  Please give the ability to add more imaging passes and to customize the passes.
  Please give the ability to save bad sectors to log file to skip in the subsequent passes.
  Please give the ability to retry copying bad sectors from the log file.
Thank You
Logged
Pages: [1] Go Up Print 
« previous next »
Jump to:  


Login with username, password and session length

Powered by MySQL Powered by PHP Powered by SMF 1.1.20 | SMF © 2013, Simple Machines Valid XHTML 1.0! Valid CSS!