Hard Disk Drive Myths Debunked!

Discussion in 'Reviews & Articles' started by Adrian Wong, Mar 16, 2004.

  1. power

    power Newbie

    <quote>Hello power,

    Actually, I covered this in Myth #17.

    It is possible to format or use some software to "hide" bad sectors but it doesn't really repair them. All a low-level format or that software you mentioned do is replace bad sectors that they find with free sectors on spare tracks found in every hard disk. This is essentially what happens to every hard disk at the end of the manufacturing process.

    As you mentioned above, there is a limited number of bad sectors that the software can "repair". That is because the number of spare sectors is limited. Once the spare track is used up and there are no longer any spare sectors, then low-level formatting or that software will not be able to hide additional bad sectors.</quote>

    If you suspect that your disk drive is damaged and contains bad sectors, don?t hurry to throw out the disk and don?t think that your important information is irretrievably lost. Take advantage of HDD Regenerator - the unique software program for regeneration of hard disk drives. Almost 60% of all damaged by bad sectors hard drives have incorrectly magnetized disk surface. Our researches have been fruitful and we have found algorithm which is special sequence of high and low level signals. These signals are generated by the software and they switch damaged surface. Even low level formatting is not able to handle this task! HDD Regenerator regenerates bad sectors by magnetic reversal. If your hard drive is damaged by bad sectors, the disk not only becomes unfit for use, but also you risk losing information stored on the disk. HDD Regenerator will regenerate your hard disk. As a result, not readable damaged information will be restored. With all this going on the existing information will not be affected!

    if you actually clicked the link i put in and read the above paragraph quoted from the website read the above you would note that hdd regenerator restores the bad sectors unlike what the software in something like hitachi's dft does making the data in the bad sectors readable again they are actually restoring the bad sectors, i understand what most software does and what you have based your myth on however hdd regenerator does not work the same way! If it did regenerated drives would need to be reformatted and have a loss of data this is not the case with hdd regen quite often we will have drives which have 1-30 bad sectors at the start of the drive and they will not boot into windows and just get stuck in a rebooting loop, drive regen will recover them and the drive not only is usable again but will boot into the OS, you can dismiss this software and place it into the basket with all your other hdd repairing software or you can try it for yourself next time a drive of yours develops bad sectors.
  2. elkinm1

    elkinm1 Newbie

    Hi, I once got a refurbished hard drive which came with bad clusters after a format. Later on I reformated it but the bad clusters dissapeared, but then with a detailed norton surface scan they showed up again. After that I kept finding more and more bad clusters but the drive was working fine. Well within a total of two months the drive died completely. Since then I hate refurbished drives and any drive that came with bad clusters I instantly return.

    Basicly a WD 80GB SE HD recently died on me with a single loud click without any warning of any kind or any real noticable strain. RMA dep. says they send out refurb drives which imedietly makes me nervous as its like storing data that I am begging to lose, but I don't want to waste the drive.

    So basicaly any idea why the drive failed and how crapy are WD refurb drives.

    I know it is not a direct myth but it nicely covers some myths.

    Thank You
  3. crackerjack

    crackerjack Newbie

    its a fair point, the magnetic domains will tend to 'blur' up over time. Really depends on the quality of the media and the 'difficulty' of the pattern the domains form on the media as to how long it will be readable for.

    As far as disk orientation goes, once upon a time, running a hard disk inverted was a big no no. It would cause abnormal bearing loading and could cause premature failure. I'm not sure how FDB based drives will cope with being run upside down, depends on how the assembly is presurised. If it only pumps up one side, then running it upside down may have nasty consequences.
  4. CypherPhuck

    CypherPhuck Newbie

    Great article as usual, Adrian! Keep it up! :thumb:

    You can't just say that he is spreading myths himself, crackerjack. You have not provided a single shred of proof.

    But I agree with you that many hard disks now use energy from the spinning platters to move the heads but to say that Adrian is wrong is also wrong.

    I point you to this guide by StorageReview.com.

    Here is the link - http://storagereview.com/guide2000/ref/hdd/op/actParking.html

    You have the technical knowledge, crackerjack. But you might want to soften on your approach. I have known this site to be really acceptive of constructive criticism. Just tell them if they made any mistakes. There is no need for any macho show off of technical expertise. :mrgreen:
  5. TungstenBoy

    TungstenBoy Newbie

    harrrrr.............r u sure??????.............the magnetic field in the hard disk can blurrr????? :shock: :shock: :shock: :shock: .........where did u read dis....?????? :think: :think: :think:
  6. zy

    zy zynine.com Staff Member

    might be true... i wonder what happen if you place a very strong magnet to the hard disk .. :p ..

    floppy disk data sure.. gone..
  7. coreying

    coreying Newbie

    Your article was rather good... but as with the previous comments about too much power causing failures and other generalised statements with are not necessarily wrong, but not right either (like landing zones, and orientation of hard drives), you have made another incorrect comment here.

    Hard drives are NOT sealed! Yep... that's correct. Check it out for yourself, there is usually a little hole on a harddrive which is visible... it sometimes even says something like 'do not cover' etc. It's not always visible to us without pulling the harddrive apart, but it is there.

    The reason ?
    As soon as you start moving the platters and heads, friction in the environment (ie, platters moving in the air) causes heat, and also heat from the bearings and other electronic/mechnical devices causes the air to expand. Thus it needs a way to escape.

    Also, to add to the cheap power supplies debate - there are studies available which shows that power causes many hardware failures (not just with computers). It's not only the oversupply of power, but the undersupply or _irregular_ supply of power. It doesn't usually cause problems with are immediate or obvious (ie, platters spinning up and down etc), but over time causes unnecessary stress on electronics and mechnical items and thereby increasing the likelyhood of failure. Some studies claim that companies using good quality powersupplies AND power conditioners have up to 80% less hardware failures than companies who arent.

    I will also support power's posts about the software utility called HDD Regenerator. Doing technical support in an environment with over 9,000 computers (laptops/desktops/servers), this piece of software has proven invaluable. The fact that it can actually restore data from sectors which have been marked bad, all without formatting, is great. It doesn't work all the time, but considering it's doing something you'd have previously thought was impossible for any software to do, it's awesome.
    Anyone who does not look into that further is only causing themselves a disservice.[/b]
  8. peaz

    peaz ARP Webmaster Staff Member

    Yup TB, it's correct that the magnetism on the disk platters can 'blur' after a long time. This is especially true if the section of the disk do not gets re-written over a long period of time. You see, when u read and write on the disk, the sector gets remagnatise back. So it sort of like 'recharging it's magnetism power'... sort of. That's why some ppl actually recommend defragmenting your hard disk often becuase it moves your files around and in doing so, it newly placed data is written with 'newly charged' sector...so to speak.

    I remember a utility called "HD" a long time ago with the capability of recovering data from bad secotes of floppies. TO me and my friends, that utility was like 'the god of utilities', we made sure everyone had a copy.. no, TWO copies in case one went dead, we carry them around in a floopy like a true geek would, and we copied it to any PC we encounter... I believe this is similar with the HDD Regenerator does as well, it tries to read over the bad sector countlesss times in an attempt to retrieve the data from there.. and yes.. i do agree it works.

    But I've been in discussion with Adrian on this already, in the guide, he actually meant that a real bad sector... irrecoverable ones, cannot be saved. This means physically damaged platters. The Myth was that a reformat or recovering utility that low level formats 'seems to rejuvinate' these sectors when what they really do is to use the spare track. He didn't really dispell off this regen utility that REALLY read from the bad sector in an attempt to recover the real data there. :D
  9. zy

    zy zynine.com Staff Member

    yes thats true... it has a hole with special filter which prevents dust from entering
  10. lillepede

    lillepede Newbie

    Myth #16

    > Some bad sectors are "virtual" bad sectors that can be repaired by
    > formatting the hard disk.

    I think this misconception is founded in that some harddisks (like IBMs) contain an extra area of sectors, which can be used instead of bad sectors. This way you retain the available storage eventhough sectors have gone bad. Well, at least until the disk runs out of extra sectors.
    This is the case with the 75GXP series, which I had the "pleasure" of dealing with.
    You need to use IBM-tools and to do a low-level format for the swap to occur.

  11. Adrian Wong

    Adrian Wong Da Boss Staff Member

    Err.. Actually, I only said sealed, not hermetically sealed or airtight.

    What I meant by sealed is that the hard disks are permanently enclosed within a case. Yes, there is at least one vent hole for barometric equalization.

    There are some hard disks that are hermetically sealed. They are used in military applications which require the hard disks to be used in high altitudes.

    I have to be honest. I really wonder about the basis behind this software. Maybe all it does is swap sectors on the go. But I have just been told that new hard disks do that anyway. Hmm.... :think:

    BTW, I was supposed to update the guide sometime ago but I haven't found the time yet. Please hang in there for a while. I will do my best to clarify everything and if I have propagated any myths myself, I assure you I will correct them.

    Thanks! :mrgreen:
  12. TripleA

    TripleA Newbie

    HDD Regenerator


    I was just as sceptical about HDD Regenerator when I first read about it. But later experience seems to indicate that it does actually work as-advertized. I.E. a lot of bad sectors are repaired, but not all. It works with drives other tools couldn't recover (and I usually use it last, for reasons I'll soon explain). And I haven't noticed any patterns to exactly how many sectors get repaired. On one drive not a single sector will be repaired, while on another a few hundred or thousand will be. The results are consistant on the same drive over several runs, and the data always came back, in my experience.

    So it's a *very* useful tool, in my experience.

    But there is a catch. Quite a big one: it's *very* slow. 9 to 10 seconds per sector recovered. Which can add up pretty quickly.

    Example: as I write this, HDD Regenerator v1.41 is running next to me on a 60GB IBM Deathstar. It has been for about 5 hours and 20 minutes. So far, it's gotten through ~69000 sectors. Of those, 1985 sectors were recovered. That's about 3% of sectors done so far. At this rate about 3.5 million sectors will have to be recovered from this drive. That'll take about 9 thousand hours. A bit over a year.

    I think it can very strongly be argued that a 60GB HDD is not worth that much effort.

    I'm hoping only the start of the drive is damaged, though, so I'll give it a couple of days before I pull the plug...

    Speaking of which, does anyone have any idea of the typical damage pattern on IBM Deathstars? Note that I'm not sure this particular drive actually suffers from the same ailment that gave the Deathstars their name. It does make a weird kind of soft clicking sound that I haven't heard any other dead HDD make. And I've listened to a few, over the years.

    P.S. About old floppy-age tools: I remember the local holy-Grails: PCTools DiskFix & VGACopy, whatever the name stood for. Real life-savers, both of them were.

    [Edit: re-ordered some stuff to make it easier to understand.]
  13. Adrian Wong

    Adrian Wong Da Boss Staff Member

    Hello TripleA,

    How many bad sectors are on that 60GB Deathstar? :shock:

    9-10 seconds per bad sector is very slow... :shock:

    I have actually asked several hard disk companies but so far, everyone has refused to comment on it. I wonder why... :eh:
  14. TripleA

    TripleA Newbie

    I wish I knew. Would help me calculate how old I'll be when it's done. :)

    The data is of some importance, anyway, so I'd probably have run it through Regen in any case...

    BTW, it's now gotten through a shocking ~1057000 sectors (About a million of them in about 5 minutes, since they were clean. Gives one some hope...). So far it had to recover ~11400 sectors. And that took it just about 31 hours and 3 minutes. That's an average of ~9.8 seconds per sector.

    As I said, a useful tool. But of limited applicability.

    Do please let us know if any of them makes any comments. I'd really like to know how it works. I have my theories, but most of them would require a kind of raw HDD read/write mode. Which, AFAIK, does not exist. Not to mention that HDD Regenerator seems to be chipset/HDD model independent...
  15. Adrian Wong

    Adrian Wong Da Boss Staff Member

    ROTFL!! :haha:

    Sure! I will definitely post an update if I ever eke out any response from any hard disk manufacturer about the utility! :mrgreen:
  16. Dashken

    Dashken Administrator!

    Hard Disk Drive Myths Debunked

    This guide was written in response to the numerous fallacies about the hard disk that are still being propagated in many forum discussions. Although many articles have covered these topics, it is apparent that hard disk urban legends are still more popular than the simple truth.

    So, let's get down to basics and examine some of these common fallacies or myths and debunk them!


    Link : Hard Disk Drive Myths Debunked
  17. m0dD3r

    m0dD3r Newbie

    Wow! Awesome guide man! This has answered a TON of questions I had about HDD's. I have forwarded to all my computer friends for reference. I look forward to this being updated even more.

    Also, let's say I had a computer that was running a torrent client so it constantly had new files being added to the hard drive every day. Would it hurt the hard drive to defrag it every 3-7 days? I would be using perfectdisk 7 if you need to know.
  18. Adrian Wong

    Adrian Wong Da Boss Staff Member

    Thanks! :beer:

    Nope, even defragging that frequently should not hurt it at all. In a way, frequent defragging is actually less stressful because each defrag session would take much less time than a long-delayed defrag.
  19. chunkie

    chunkie Newbie

    That's a really useful guide!

    Oh.. You mentioned that formatting does not help increase the PC's performance. But.. if defragging does not improve the PC performance... should I format the PC then?
  20. Adrian Wong

    Adrian Wong Da Boss Staff Member

    Actually, the article didn't say that. I only mentioned that formatting won't kill your hard drive. Neither will defragging it.

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