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Data recovery and disk repair questions and discussions related to old-fashioned SATA, SAS, SCSI, IDE, MFM hard drives - any type of storage device that has moving parts
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Why is a head crash so difficult to solve?

January 23rd, 2019, 5:47

Usually the general consensus is that recovering information from a hard drive with head crash is very difficult, even many say it is almost impossible.

Examples:

https://vitaldata.ca/blog/unrecoverable.html
https://www.reddit.com/r/techsupportgor ... t/ck306ny/


I know that when a head crash happens small particles are scattered all over the plate, so that if we tried to read it we would crash again and generate new head crash.

But ... Could not we clean the platters of all the particles that could be and then read from the outer point of the platters to the point of the head crash?

At least, the files up to that point, could be recovered, right?. and the same with any type of damage such as a hole with a drill.

Maybe the firmware of some hard drives does not allow this "selective reading" action?
Attachments
Hard_disk_head_crash.jpg

Re: Why is a head crash so difficult to solve?

January 23rd, 2019, 17:06

Everything what you said is working, but it is difficult and slow work. Plus you need to have some special knowledge to do it and different models even of one manufacture working differently with this problem. So after all you need around 2-9 weeks to read one surface. How many people would pay for this such of work? Plus part of data will be gone anyway and you will find it out which part you lost only when you will finish part of work. There are companies which are doing this type of work but prices are around $8k and up.
Many drives has glass platters so drill will brake glass to pieces. If drive has metal platters, usually if somebody drilled platters, not only hole is problem - big portion of surface around hole is bent and can not be read in regular way.

Re: Why is a head crash so difficult to solve?

January 23rd, 2019, 18:01

" not only hole is problem - big portion of surface around hole is bent and can not be read in regular way. "

In addition, in the case of the hole I imagine that it is impossible to know exactly how far the plate is bent to send the head to that point since the tolerance is minimal and the plate needs to be exactly straight.

Re: Why is a head crash so difficult to solve?

January 24th, 2019, 4:56

drHDD wrote: Plus part of data will be gone anyway and you will find it out which part you lost only when you will finish part of work.


And, usually, when you do such work client will say that the lost data "was the most important data, and it was the reason I agreed to proceed in the first place".

Re: Why is a head crash so difficult to solve?

January 24th, 2019, 6:42

northwind wrote:
drHDD wrote: Plus part of data will be gone anyway and you will find it out which part you lost only when you will finish part of work.


And, usually, when you do such work client will say that the lost data "was the most important data, and it was the reason I agreed to proceed in the first place".


I had not thought about it. You have to take a lot of risk to do the work or to charge the client in advance to recover something or not ... :?

Re: Why is a head crash so difficult to solve?

January 24th, 2019, 9:51

northwind wrote:
drHDD wrote: Plus part of data will be gone anyway and you will find it out which part you lost only when you will finish part of work.


And, usually, when you do such work client will say that the lost data "was the most important data, and it was the reason I agreed to proceed in the first place".

In such low chance recoveries, I think it is important to pass the risk over to the client...at least a significant portion. So, if you are quoting them $10,000 for the job, require 50% as a non refundable down payment and if they change their minds or decline the recovery because the file that they want isn't there, they don't have to pay the remaining half, but you keep the down payment to cover some of your time spent on the case.
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