CHKDSK...I'm a dummy

Discussion in 'OT Technology' started by Gen5_EG, May 25, 2008.

  1. Gen5_EG

    Gen5_EG :)

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    So my computer was acting funny, random freezing all over the place. Some idiot friend of mind said to run CHKDSK. So I did. The computer runs it in and I'm like, okay, I'll just continue to do whatever I was doing. So I'm surfing the web and all of a sudden, the computer freezed again. So I hard shutdown and reboot. Next thing that comes up is that my OS cannot be found and when pressing the setup (dell computer) it shows that my hard drive is UNKNOWN. Did I totally fuck this up and wipe my drive clean? Or is there a way that I can recover all my shit? Becuase if I boot the computer, it will just give me 2 options, to strike the F1 key which does nothing and to run the setup. Please tell me there is a way around this shit. :o
     
  2. Doomsday

    Doomsday XXX

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    use disk tools to recover
    i recommend testdisk
    http://www.cgsecurity.org/wiki/TestDisk
    this fixes boot sectors and corrupted partition tables.

    as for random freezing, it could be a lot of things.
    bad ram, bad drivers, bad software, etc.
     
  3. awns729

    awns729 New Member

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    check disk probably didn't mess up your comptuer, i bet something else was wrong.



    one thing you can do is download ubuntu[link]. put it on a CD and make your computer boot from the CD (you'll have to press an F button to change the boot order as soon as you start your computer). once ubuntu starts loading, go to the first option (start/install ubuntu). once it loads you can find your hard drive and check to see if it can be accessed. hopefully you have an external HDD or DVD/CDs to back up onto, but if your HD can be accessed from there you're fine. also, you can use internet/AIM/word processing programs right off the CD if you want.

    ubuntus a godo way to back your stuff up and reformat (or even try to fix the drive with what doomsday said)
     
  4. deusexaethera

    deusexaethera OT Supporter

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    I've discovered that by the time CHKDSK actually finds problems it needs to fix, you're already in pretty deep shit. So, it's a crapshoot whether fixing those problems will help or hurt. Sounds like it hurt in your case.

    Next time, defrag more often. Defragging moves the data around on the disk, and aside from any performance benefits, moving the data means that it has to be read, error-checked, and re-recorded. That keeps the data fresh and helps to head off catastrophic failures like the one you just had.

    Live and learn.
     
  5. Mike99TA

    Mike99TA I don't have anything clever to put here right now

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    You realize how ludicrous that sounds right. Keeping your data fresh? This is digital data, not analog, it doesn't get "fresher" when it gets moved. If its corrupt its corrupt it doesn't matter if you move it or not. Moving analog data to new media can keep it fresh (like a VHS tape) but digital data doesn't change when you move it, thats sort of the entire benefit.
     
  6. deusexaethera

    deusexaethera OT Supporter

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    All hard drives lose bits from time to time, and there are known and proven algorithms that can figure out the missing bits with 100% accuracy by analyzing the surrounding data -- but if the missing bits are actually corrupt, and not just mis-read by the reader coils, they'll only get rewritten when the OS tells the drive to rewrite the data. Also, any magnetic medium will degmagnetise over time, particularly when exposed to heat, and the only way to protect the data from getting "smeared" by that demagnetisation is to rewrite it periodically; again, with anything less than the most expensive HDDs available, this will only happen when the OS tells the drive to read and rewrite that data. Defragging is the easiest point/click way for an end-user to make sure this happens.

    If you think that's ludicrous, you should lurk more. Or...I dunno, maybe you are right, and it's only through pure luck that every single person I've told to defrag on the 1st of every month has never lost a drive to data corruption.
     
  7. P07r0457

    P07r0457 New Member

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    statistically speaking, drives that are defragged often are actually more likely to fail.

    Not saying defrag is a bad idea... but the notion that it's going to magically save your drive is recockulous.
     
  8. Doomsday

    Doomsday XXX

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    even if you rewrite periodically, you can still suffer data loss/corruption if the surface it writes to has problems.

    defrag pretty much just relocate shit to reduce file fragmentation.

    this is why it is recommended to use disk diagnostic tools to perform surface scans and check for errors before you defrag to ensure file integrity.
     
    Last edited: May 26, 2008
  9. Mike99TA

    Mike99TA I don't have anything clever to put here right now

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    While a vague bit of what you're saying is true, defragmenting your hard drive is not going to fix it. Running a scandisk with a surface scan can help keep data off of corrupt sectors.

    I've been using Computers for 20 years now, and I've yet to have any hard drive corruption on a home PC and I assure you it has nothing to do with me defragging my hard drive a lot (because I don't). The only time I've ever had a hard drive issue at all was a few years ago when I had a head crash, never anything other than that.

    Also what does lurking have to do with figuring this stuff out? Sometimes when I lurk in this subforum I feel dumber reading the ridiculous answers people give. Also look at my join date and my number of posts its hardly possible for me to lurk more. :hsugh:
     
  10. deusexaethera

    deusexaethera OT Supporter

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    They may be statistically more likely to fail mechanically, I'll give you that, but I've only ever seen two disks that failed mechanically at all -- the rest just lost data to corruption, and nearly-corrupt data can only get fixed when the data is read and the errors are noticed. Defragging requires that all the data on the drive gets touched at some point, which means that all of the data on the drive will get error-checked and cleaned up -- no magic involved.

    Most hard drives never get used long enough to even approach the limits of their mechanical lifetimes, so why not spend some of those unused MTBF hours on keeping the data intact instead?
     
    Last edited: May 26, 2008
  11. deusexaethera

    deusexaethera OT Supporter

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    Not anymore, at least not very often. As Jolly pointed out to me a few months ago, modern hard drives have extra space that they dynamically allocate to "replace" bad sectors on the fly -- that's why CHKDSK almost never reports any "bad" sectors anymore that can't be fixed by reformatting, because all of that slack space has to get used up before anything outside the disk's circuit board even becomes aware that a sector has gone bad.
     
    Last edited: May 26, 2008
  12. deusexaethera

    deusexaethera OT Supporter

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    Well, you could not post at all. :mamoru:

    Seriously though...

    Yes, a thorough surface scan on a single disk can catch persistent data errors and relocate the data before it degrades to the point of being unreadable. However, since the "disk surface" that the OS is aware of isn't necessarily real "disk surface" anymore (see previous post), a surface scan isn't guaranteed to do anything useful. Also, with the increasing prevalence of RAID arrays, surface scans are totally useless because the "disk surface" on a RAID array is 100% theoretical; what the OS sees is just a vague abstraction that the RAID controller shows to it, and the controller itself is actually responsible for dealing with data errors. So in that case, the only useful part of CHKDSK is the basic filesystem scan that makes sure all the checksums and journals and whatnot are kosher.

    Furthermore, if you've ever timed a thorough surface scan (I have), you'll notice that it takes about as long as defragmentation does. So, if you're going to have hours of downtime to make sure your 1's and 0's are black and white instead of varying shades of grey, you're better off running defrag instead, because all of the same error-checking is going to happen anyway, and you'll get the performance benefits of cleaning up the filesystem as well.
     
  13. Mike99TA

    Mike99TA I don't have anything clever to put here right now

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    Not to keep this silly discussion going but the only files a defragmentation actually modifies on the system are the ones that are fragmented (surprise surprise). As the system goes through the files if a file is 100% contiguous it does not modify that file in any way. It knows whether a file is contiguous or not by checking the list of inodes pointing to the parts of the file and makes sure they're all next to each other on the disk. If they're not it moves the parts together into an open spot on the disk.

    I have no idea what is "average" but I'd guess on most systems less than 15% of files get moved during a defragmentation. On a brand new system there should be and usually is 0% fragmentation and it only starts becoming a problem as programs are uninstalled and if there are any programs that modify large amounts of files.

    Regardless, you're just as likely to "touch" all the files defragmentation touches just by using the system anyway. Everything defrag modifies is data you're already using on a regular basis anyway (thats why its fragmented) so its already getting used constantly.
     
  14. deusexaethera

    deusexaethera OT Supporter

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    That depends on what kind of defragmenter you use. Mine rearranges files according to how often they get used, so basically every bit on the drive gets rewritten once a month. I'll grant you that the Windows Defragmenter doesn't go that far, but it does compact files automatically, meaning that even files are contiguous, if they're scattered across the disk, they'll get moved.
     
  15. trouphaz

    trouphaz New Member

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    Wirelessly posted via wap.offtopic.com (Mozilla/2.0 (compatible; MSIE 3.02; Windows CE; PPC; 240x320) BlackBerry8703e/4.1.0 Profile/MIDP-2.0 Configuration/CLDC-1.1 VendorID/105)

    Man, you love to talk out of your ass. The original post was about a PC which the majority of use single drives with no RAID controllers. Yet, you try to pull out all kinds of BS to save your failed argument. I once did a defrag without a scandisk and it actually caused a failure. Luckily, running a full scandisk actually saved my pc. Defrag on its own isn't the greatest.
     
  16. deusexaethera

    deusexaethera OT Supporter

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    Defrag doesn't fix filesystem errors, no. Some defraggers will scan for filesystem errors before defragging; I don't recall if the Windows Defragmenter does that or not.

    I wasn't talking out of my ass. I was listing all the ways that a full surface scan isn't particularly useful, some of which apply to the OP's situation and some of which don't. The one about RAIDs doesn't apply, but the one about disks compensating for surface defects on their own (up to a point) does apply. Pardon me for going into too much detail, but if I didn't, someone would've brought up RAIDs to contradict me. You know they would; they're everywhere, watching and waiting for me to be imperfect so they can make me look like a fool.

    You don't know what it's like, man, you just don't.
     
  17. critter783

    critter783 OT Supporter

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    I don't think the chkdsk caused your problem. You can't run chkdsk with the repair option on a volume that is currently mounted. You can run chkdsk, but all it will do is report some statistics about the volume. In order for it to actually change anything on the drive, you would have to boot to some other media and run chkdsk on the drive. My guess would be you've got a bad drive. The boot sector is already corrupted, and the random freezes could be caused by delayed write failures, which will freeze your computer if this happens to a page in virtual memory that contains windows OS process data.
     
  18. awns729

    awns729 New Member

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    If you try and run chkdsk once windows is loaded, it instead (for XP) runs the next time you start windows, and in my experience it has deleted/fixed files when it runs on your next startup.
     
  19. critter783

    critter783 OT Supporter

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    That is true, but after reading the first post, I sort of had the idea that he just ran it and continued using the computer while it was running. If that's the case, it wouldn't delete or fix any files.
     
  20. awns729

    awns729 New Member

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    Ah, true. Not sure if that's even possible to do anymore though lol at least in xp sp2-3?
    Gen5, any updates?
     
  21. dissonance

    dissonance reset OT Supporter

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    By this I am guessing you didn't shutdown the computer but just killed it and turned it back on? This could have been the cause of your problem. Windows is constantly reading/writing its files and if you killed it during a write it could have corrupted the file.

    Bottom line: Checkdisk isn't what killed your computer. It was something else. As others suggested, try to copy your data off the hard drive and reformat/reinstall windows (assuming their isn't a real hard drive issue here).
     
  22. Gen5_EG

    Gen5_EG :)

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    Didn't try anything as of yet. Going to bring it in to the office for someone to take a look at it. He said he has a disk that will fix the problem. I'll keep you folks updated.
     
  23. awns729

    awns729 New Member

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    just to satisfy my curiosity, could you find out the name of hte disk? i'm always looking for good recovery software and what not. thanks
     

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