February 1st, 2012, 7:31
February 1st, 2012, 9:26
February 1st, 2012, 13:08
February 1st, 2012, 13:33
hddguy wrote:Without professional diagnosis it is difficult to identify the exact problem.
I would assume that the spindle is trying to power but badly parked heads are causing resistance and the audible sounds you hear is failed attempts at starting the motor.
If this is the case each time the media is powered the attempts to start the spindle while recording heads are 'stuck' to the surface is causing more damage.
You need to get this professionally diagnosed. Further attempts to power or DIY repairs will probably only result in further complications.
February 2nd, 2012, 3:11
February 2nd, 2012, 4:09
February 2nd, 2012, 4:57
northwind wrote:This drive is most probably suffering from stiction (at least).
This means that you can take the safe route and consult a pro, or try diy and complicate things even further.
I don't understand why you ask the additional questions. If you want to attempt DIY by opening up the cover etc using someone's guidance then i'm afraid no pro would consult you or guide you to it.
February 2nd, 2012, 7:37
February 2nd, 2012, 7:45
February 2nd, 2012, 8:08
HDD Spaz wrote:Just when I think I have seen it all - Toenail recovery!
February 2nd, 2012, 8:38
hdrescue wrote:Hello
That is badly parked heads almost for sure. And like the guys told you, you have really good DR professional in Europe.
I work from Portugal and I can help you to if you need.
You know the drive need to be open in a clean environment and more than that is about knowledge and DR specific tools.
Of course we don´t share information that takes years to learn, develop and investigate.
February 2nd, 2012, 8:59
February 2nd, 2012, 10:17
XXL wrote:Before taking it to a tech. I would like to know as much as possible about the potential procedure that is going to be undertaken and learn a few things here and there while I have the chance - is that a bad thing?
February 2nd, 2012, 11:08
hddguy wrote:Here is an example of stuck heads:
http://www.youtube.com/watch?v=7c_MTX6-gYg
In this example the slider has become detached from the head assembly. Attempts to repair by the 'technician' here results in further damage and parts would then be required, though the chances of damage to the media surface would now be significantly higher.
It is very possible the magnetic heads in your disk are also damaged, and possibly your case cannot be restored without the use of parts, but all this needs to be identified during a professional diagnosis.
Once the HDD is operational it will very likely have some logical damage to the surface, i.e bad sectors. Even for this specific recovery or cloning hardware / software is required. Even at this stage your data would not yet be safe.
there are too many potential complications for DIY.
You are right in that there is lots of information about this problem here, and the fact that there is a 'Search' button means it can be found with minimum effort on your part.
Mostly, people do not have the time to explain in detail the same problem over and over each time a new member asks about it.
People here are helpful and quite a lot of information is shared, though in my opinion this only encourages DIY which results in increased costs with a professional lab and compromises the recoverability and safety of potentially important data.
What you decide is your choice, but realistically you need to consult a professional who can handle this
February 2nd, 2012, 12:40
XXL wrote:I woud like to ask why is gddrescue perceived to be a better tool than dd - they seem to recover the same amount of data?
February 2nd, 2012, 18:57
Vulcan wrote:XXL wrote:I woud like to ask why is gddrescue perceived to be a better tool than dd - they seem to recover the same amount of data?
In theory it would be possible to duplicate the behaviour of GNU ddrescue (package gddrescue) by using dd, if the technician involved was very skilled and if they made no mistakes during the process. However in practice, using ddrescue requires less skill (though it still needs some skill for best results) due to its built-in algorithms & logging, and typically has better & less-risky results, partly due to preventing the human errors which could otherwise easily occur if trying to use dd manually with many different parameters, and making it easy to control the relevant tuning of those parameters. The specific benefits of using ddrescue also depend on the problems with a given disk (e.g. just one unreadable block on the disk, or 1000 marginal blocks in different places on the disk which might be readable with extra retries, or ... etc. etc.)
In short, the advantages of using ddrescue make it a "no-brainer" choice over dd, for reading from imperfect disks (and in some other situations), in my experience.
(Note: This is just comparing ddrescue & dd - it does not address the risks / problems which are common to using either program.)
February 3rd, 2012, 8:53
February 3rd, 2012, 11:27
Vulcan wrote:I counted around 14 separate points / questions where you seem to be expecting a reply - some of which would need multiple paragraphs per response. At a conservative 10 mins per detailed paragraph, that's over 2 hours of my time that it would take to reply, so I'll politely decline to do that.Perhaps someone else here is less busy and has that time... But here are a few brief comments.
Some of your questions are answered in the online ddrescue manual (e.g. the algorithm section - changing the block size is not all that it does); several others are hypothetical questions where the data necessary to give a detailed reply are not (and cannot be) provided by you, without having a specific faulty disk available on your system and mine, to test any hypothesis. So for many questions, the answer is "it depends on the specific behaviour of the disk...". Faulty disks can behave in many different ways which are different to your suggestions above. I've learned not to get into such hypothetical discussions here - they just go on & on, as it is impossible to know when a "correct" (or "the best possible") answer has been given.
Finally - yes, you should expect different behaviour between dd / ddrescue & MHDD, because the error recovery / retry / timeout behaviour in Linux drivers are completely different to MHDD. That does not mean that ddrescue isn't a useful tool, when used in ways that minimise its limitations, in an amateur (i.e. not a professional) recovery situation, if nothing better is available to perform cloning, and if the risks of such DIY are accepted. Modifying the OS drivers to adapt their behaviour can also help, but that's a whole different skillset...
I hope someone with more time comes along and answers all your questions, but personally I think you might be expecting a bit too much with your level & quantity of questioning.
GNU ddrescue manages efficiently the status of the rescue in progress
and tries to rescue the good parts first, scheduling reads inside bad
(or slow) areas for later. This maximizes the amount of data that can be
finally recovered from a failing drive.
The standard dd utility can be used to save data from a failing
drive, but it reads the data sequentially, which may wear out the drive
without rescuing anything if the errors are at the beginning of the
drive.
Other programs switch to small size reads when they find errors, but
they still read the data sequentially. This is a bad idea because it
means spending more time at error areas, damaging the surface, the heads
and the drive mechanics, instead of getting out of them as fast as
possible. This behavior reduces the chances of rescuing the remaining
good data.
February 3rd, 2012, 13:28
XXL wrote:Thank you for your time and effort, Vulcan!
XXL wrote:I am under the impression that most of the questions that I have asked can, by all fairness, be grouped together, as I am basically asking the same thing with 3-4 question marks
XXL wrote:so I am happy with anything that I get as a reply, either way.
XXL wrote:My main intention here is clarifying whether gddrescue lives up to being perceived superior to dd in terms of the end result (amount of data recovered!).
XXL wrote:I do not understand how is gddrescue supposed to recover any more data than dd?
XXL wrote:Overall, I am not asking for major details or anything that massively technical
February 3rd, 2012, 13:29
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