Hi,

I am quite new to this recovery stuff so please go easy...I'm in need of some direction in order to continue rescuing my data. Sorry for the long post, I have numbered the questions throughout to help with potential response.

Not long ago, I had a mishap with an external Seagate drive that contained essentially all my family photos and videos. The drive hit the carpeted floor from about 18" while it was spinning. Apparently that was enough to do it in. With the assumption that the heads were damaged and after pricing out data recovery services involving internal hardware repair, I decided I couldn't afford to go that route. So I went the DIY route.

After removing the drive from it's enclosure and obtaining the pertinent info off the drive label, I sourced a donor on eBay and went to work. After performing a head stack swap in a hepa clean air environment, I proceeded with using GNU ddrescue via System Rescue CD. So far I have been able to get to approximately 40% rescued according to to ddrescue. Though, I seem to be hitting a bit of a road block. After starting ddrescue, it will run for an arbitrary length of time before the 'current rate' drops to zero. I can get things going again by using Ctrl-C and disconnecting and reconnecting the source drive SATA cable, then checking with probe simple to make sure the disk label didn't change, and finally restarting the process.

Sometimes I can get through a few hours of success before this happens, sometimes only minutes. From reading around on different forums, it seems there is no command to power cycle the source drive on the software side of things. Short of sitting at my desk and power cycling this thing for the next month, I don't know what to do about this.

1. Does anyone have any suggestions on how I might mitigate this issue?

Another thing is this...there is only one folder that I really have any interest in rescuing. Before attempting the rescue I mounted the drive to test it for a moment and found that I could view the folder structure and I could see the folder I need. (Photos and Videos)

2. Is there a way to only focus on this section of the disk during the operation?

After making it this far I also realized that I should have potentially been using the disk labels to do the recovery as opposed to the device label (individual partitions). Although, I think I may be okay so far? As I have been reading a partition and writing to a partition.

3. Will I need to rescue the first partition also? Or is that unnecessary?

I have seen that there is a firmware section on this site. This isn't something I have really looked into, as I attempted to source a donor drive that is as close to the original drive as possible. Paying close attention to the variables in the firmware numbers, serial numbers, site codes, heads map, etc...

4. Is it possible to flash a firmware that would allow for better compatibility between the original drive and the replacement heads?

5. Lastly, once I have recovered as much data as I think I will be able to obtain. Is it okay to view the contents of the new disk on a Windows OS? After viewing, can I continue a rescue attempt? Basically, what is the safest way to view the progress I have made with out messing up the ability to continue recovery?

Any information is much appreciated. I have made it this far and would hate to fail at this point.

Thank you.

Before I answer any of the questions, I would like to point out that the non-trimmed size seems very high, and it is not a good ratio compared to the amount rescued. I would not give this a high success rate.

1) Without an expensive hardware imager, your only hope for automatic power cycles is some sort of relay setup, along with software to control the relay, and also write a script to control ddrescue and the relay.

2) There is one (complicated) possibility here for targeting specific files using ddrescue: https://sourceforge.net/p/ddrutility/di ... /e17d000c/

3) You should not need to recover the first partition to recover data from the second partition. Your biggest concern is that if the drive degrades and becomes unable to retrieve the partition information, you will no longer be able to clone it as you are, since you are cloning a partition instead of the whole drive.

4) NO!!! Don't even think about trying to update the firmware, you would most likely kill the drive in the condition it is in.

5) The best idea is to use some method that mounts the partition as read only. You can do this in Linux with a loop device. Letting Windows have direct access would be a last resort. You don't want it making any changes to your only rescue copy. If you had a third drive large enough and made a copy of the clone, that would be safe as long as you keep the original copy unaltered. But that would be a task with a 4TB drive.

Good luck

And to add to all that was stated already if it's a SEAGATE drive you might be able to maximize the chances of recovery if you disable background processes like defect managment and relocation, etc ....

You can do that using a TTL adaptor like this - http://www.hddoracle.com/viewtopic.php?f=46&t=192

Plug it like this - http://www.hddoracle.com/viewtopic.php?f=6&t=193

And issue ONLY the following commands :

http://www.hddoracle.com/viewtopic.php? ... =60#p10834

If you are lucky you will be able to clone the drive without it getting off-line and without the need of power cycle it ....

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This is all very interesting. Thank you for the reply. Pardon the delay as I have taken a break from it for a while. It's weird that you mention the relay/script method...as I just sat down to start tinkering with it again and began planning a method to use a separate PSU and a relay to cycle the drive at set intervals and attempt to resume the recovery. Then I logged into the forum and saw your response.

I can easily setup a relay to the the cycling, but I'm still trying figure the best way to accomplish the commands automatically in sync with the power cycle. I have even started to think about writing some sort of a simple Arduino program that could mimic keystrokes. Not sure...do you have any ideas?

One thing I would have to accomplish first though is force the drive to be assigned the same device name on each power cycle. It tends to move around. Sometimes it is assigned /sda and sometimes /sde which would obviously screw up the commands.

The reason for the large non-trimmed count is due to being unfamiliar with ddrescue in the beginning. I plan on restarting the recovery.

Nevermind, I think I have the device name thing sorted by using /Dev/disk/by-id

VERY BADDDDD IDEA !!!

First of all use the commands that i did mentioned with the TLL adaptor. Then try to clone the drive.

You don't want to power cycle the drive AT RANDOM !!!

The idea of the "relay" would be to power cycle the drive if and when it gets stuck at BSY or starts to only produce errors and for that you would need to monitor ATA registers and cycle the power if the drive is stuck at BSY when reading for example a specified LBA and the copy can't be resumed by issuing a soft reset !!!

You should use Sof-Reset FIRST !!! You don't want to power cycle a bad drive more than what you need .... It's way better to power it on and copy data as far as you can then cycle the power and have the drive read firmware again and re-initialize and test itself for defects.

Imaging that while you are reading the data the drive starts to add defects to the pending list and the list gets damaged. You power off/on the drive and translator is gone or you have firmware issues .... like Samsung with A-List problem or Seagate might get bad S.M.A.R.T. data, etc .... you only want to power cycle if it's NECESSARY and if you can't regain normal access with soft reset.

Also you don't want to be copying the data in a good way and then the drive just power cycles because you set a relay with a timer .... Doesn't make sense .... You will be wasting chances to get data and the drive will have more chances to die for good.

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Ok gotcha. What program should I use with the ttl adapter? Also, how would I achieve a soft reset using ddrescue?

Something like HyperTerminal or putty will work just fine with the TTL adaptor.

I don't know if ddrescue can do "soft resets". I do have hardware based imaging/cloning tool so i do never use software only alternatives to clone/image drives.

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Since your are going to restart the recovery, I am going to suggest that you try HDDSuperClone instead of ddrescue. HDDSuperClone can detect when the drive becomes unresponsive (ddrescue can't do that most of the time), and either stop or run a command. You can use the command option to cycle a relay, as long as you have some script or program as the command. And if you decide to stick with ddrescue, at least clone the whole drive and not a partition. If you want to target a partition, use the input offset and size options.

Listen to @Spildit about using the terminal, and don't just run commands because you found a post someplace where someone claimed the commands fixed their drive. You can kill the drive very quickly with the wrong commands.

As for soft (and hard) resets, there is currently no available software only cloning tool that can perform these resets on command. It is all up to the OS when and if it performs these commands, and by that time the drive can be locked up and require a power cycle. Only a hardware imager can do the resets. (or if you happen to spend several hundred hours or more of your time to write your own personal software that can do this )

I've always wondered if controlling the POR signal (Power On Reset) would be a viable alternative to power cycling. Would the drive still spin down and then up again?

This Diamondmax example makes it easy to locate the test point, but others would require a little investigative work.


I would use an optocoupler to isolate the HDD electronics from the external POR control circuit.

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Since you said you are planning on starting the recovery over, but have potentially recovered a large chunk so far, I have to ask this. Does the destination have the exact same partition layout as the source? If you perform the command "fdisk -lu" does it show the same start and end positions for both the source and destination? If so, you would at least not lose any data already recovered when starting a full disk recovery.

Can you post the ddrescue log file? I can analyze it and give an assessment of what I see.

I would like to make a small correction to that statement. The current public version of HDDSuperClone can do soft resets, but it can only work for direct IDE mode, and it is limited to PIO. With PIO it would take forever to clone a good 4TB drive, let alone work with one that has issues which could take an eternity or longer. The option is meant to show the potential of the software, and is mostly meant for testing purposes. Just wanted to correct myself

@maximus, that would involve choosing "Direct IDE" instead of passthrough then selecting PIO ?

Yes, except it will select PIO for you, as that is the only option in the current public free version. Also the drive must be connected AFTER the OS boots, so the OS does not detect it.

Thanks, gonna play some with it.