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{RESOLVED}Scandisk & Defrag duplication?

Discussion in 'Earlier Versions of Windows' started by bilnrobn, Oct 5, 2003.

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  1. bilnrobn

    bilnrobn Thread Starter

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    Once a month I run a 'thorough' Scandisk. I use 'thorough' so the disk surface will be checked for errors. I then run Defrag by simply pressing 'ok'. I have just noticed that there is a 'settings' button that I have never bothered with. On pressing this I see that 'check drive for errors' is ticked.
    Does this mean that both Scandisk and Defrag are checking the drive for errors? It would sure cut down on the time taken if I could run Scandisk in Standard mode!
     
  2. Styxx

    Styxx Banned

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    Start ScanDisk (Start button; Programs; Acccessories; System Tools; ScanDisk); Check the Standard box; Check Automatically fix errors; click the Advanced button, the settings should be as follows - Display Summary - Always, Log File - Replace Log, Cross-Linked Files - Delete, Lost File Fragments - Free, Check Files For - check (Invalid File Names) should be checked.

    Under the Defrag Settings, just leave the default settings checked. Defrag checks for but doesn't repair the errors, if it finds errors it will prompt you to run ScanDisk and then start drag again.

    You can best run ScanDisk and Defrag in Safe Mode with the screen saver temporarily disabled (choose None).

    (tap F8 five times per second during a restart; Choose option number three (3) in the Windows Startup dialog box using the arrow keys below the Delete key, and strike the Enter key; Click Ok when prompted).
     
  3. NiteHawk

    NiteHawk

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    To set ScanDisk to automaticlly fix errors is possibly the most dangerous thing you can do. ScanDisk's function is to maintain the sanity of the file system, and if your directories or files get in the way of this objective, they will be sacrificed!

    Before you set ScanDisk to automatically fix files I would strongly suggest that you read and understand this document.

    http://users.iafrica.com/c/cq/cquirke/scandisk.htm
     
  4. bilnrobn

    bilnrobn Thread Starter

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    Thanks Styxx and NiteHawk. I understand and already do it that way Styxx, except that I have been running ScanDisk in 'thorough' and never click 'fix errors' after reading so many warnings on the dire consequences that may occur. My query was just on the duplication of the surface scan. ScanDisk runs so much slower in 'thorough' mode that running it in 'standard' mode and letting Defrag do the disk surface check is a definate advantage.
     
  5. Styxx

    Styxx Banned

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    Defrag checks for errors and if it does, simply refers you to run ScanDisk. It doesn't do any surface scan at all.

    And despite this well intentioned warning above, there is no evidence of risk by setting Scan Disk to automatically fix errors.
     
  6. bilnrobn

    bilnrobn Thread Starter

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    Now I am confused again! Does "Check the drive for errors" in Defrag duplicate something which has already been done in a 'thorough' ScanDisk run?
     
  7. WhitPhil

    WhitPhil Gone but never forgotten Trusted Advisor

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    I know Styxx believes this, but from my first hand experience, I have seen a "damaged" FAT result in Scandisk detecting a myriad of crosslinked files. And, I have also seen a corrupted fat result in an scandisk turning the entire disk directory into CHKnnnn and DIRnnnn files.

    In the event of certain errors being detected, the settings recommended above will result in deleted, lost or corrupted files.

    Basic Premise:
    There are errors that scandisk can not fix (if all problems could really be fixed, there would be no need for an AutoFix option). But most of the time, the errors detected should be correctable by scandisk. It is the one time in a hundred, or one in a thousand that the error being fixed will result in corrupted or lost files.

    Since this IS your hardrive, and these ARE your files, it is important to understand exactly what these errors are and what the fix entails (newbie or otherwise). If scandisk generates an errror that you don't understand, head to a site like this, or a search engine like google to learn more.

    My recommendations are as follows:
    1. First and foremost, never make the FIRST run of Scandisk with Autofix enabled. Scandisk can not fix all errors. All it can do is make the problem "seem" to go away.

    2. Now that you are running with fix turned off, you will be able to see each and every error, and then decide the action to take. I run with autofix turned off, and very seldom find errors. When I do, I pay close attention to the errors detected. If I have gone through bad shutdowns or other program failures, I generally allow scandisk to do the fix (if I understand the error), If it is a "new" error, I select ignore, and then do some research.

    3. Scandisk Options:
    A) Log File - I prefer Append over Replace, only because if I have a "senior moment" and run scandisk again before reviewing the log, it's no longer available. Better to just periodically delete the file as part of your routine maintenance schedule.

    B) Cross link files
    If a disk cluster gets accidentally assigned to 2 or more files, these are called crosslinked files. There is NO fix. BUT, one of the files is correct with the common cluster belonging to that good file. You just have to find out which file is still ok. PLUS, even the other files, if they are text or documents, can still be recovered. At least some of it. You just have to delete the "junk" that has appeared from the shared cluster.
    Running with the option, Copy, will copy the shared cluster and give it to all files involved in the crosslink.
    Setting the option to delete, means you have lost 2 or more files from your system that "could" have been recovered. Regardless, at the end of this recovery exercise, you must restore any questionable files involved in Crosslinks.
    (with delete set, you have to restore all files)

    C) Lost File Fragments - These are areas left in use as a result of a program failure or hard power down, and most of the time, can be deleted afterwards (C:\FILEnnnn.Chk files). (the clusters are in use, but there is no file in the disk directory that is referencing them). If you had some hangs or killed some apps using ctl-alt-del, having a few File Fragments would be normal. BUT, if scandisk detects "a lot" of them, when it asks for confirmation on what to do, ignore them. On a failing drive, or a drive with a directory problem, scandisk "could" think that much of the drive is comprised of Lost File Fragments. With the option set to Delete, a large portion of your files could be gone. With the option set to Convert to Files, your files will be gone (from the disk directory), but you will need special disk recovery services, in order to restore them.

    D) Report DOS name lengh errors - Unselect unless you need to be able to access long Windows file names from DOS.

    E) Scandisk also checks the sizes of files. The actual length versus the length contained in the disk directory. If the 2 do not match, scandisk will fix it.
    Here, I am not exactly sure what action scandisk will take.
    >> It can change the length in the disk directory to be the size that it sees on the harddrive. BUT, if the directory length was actually correct and the actual size incorrect, then you have a corrupted file that contains a cluster that it shouldn't, OR is missing a cluster that it should have.
    >> It can change the length of the file on disk, to match that of the disk directory. If the disk directory size is smaller, than the result is a truncated file. If the disk directory size is larger, I do not see scandisk arbitrarily assigning another cluster, just to make the size correct. In this case, I think it would adjust the disk directory size to match the actual size.

    With either fix, the error has gone away but you have a file of questionable integrity.

    After the first run of scandisk (with fix unselected), you will be able to review all errors found, and determine if you really want scandisk to start "fixing" them. Some errors you will be able to fix yourself by simply deleting the files involved (after attempting any salvage operations), and then subsequently restoring them.


    4. The other area where you need to protect yourself from Scandisk, is when it runs after a bad shutdown. When it does, it takes guidance from a file called \Windows\Command\Scandisk.ini.

    In that file, one should change all FIXs to PROMPTs. If an error is detected after a bad shutdown, this will cause scandisk to ask what action should be taken, as opposed to automatically "fix"ing them.

    Otherwise, it will just "Fix" them all, and as the site posted above documents, this could be disasterous.
     
  8. Styxx

    Styxx Banned

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    No,
    does not duplicate anything. Just run them both at your leisure and you'll be fine, most people don't run them at all, so you're way ahead there. I never run a Thorough scan though. If a HDD is going to go go bad it just will, and ScanDiskor Defrag will rarely pick it up ahead of time. Just be sure you do frequent backups of your sensitive data - (Internet Explorer Favorites; Netscape Bookmarks, Address Book and Netscape Mail Folders; Outlook Express Address Books and Folders (compress any Netscape Mail or Outlook Express folders first) letters, pictures, databases, spreadsheets, music, etc.) to removable media for restoring later.

    Bye.
     
  9. bilnrobn

    bilnrobn Thread Starter

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    Thanks Styxx, and to you phil for that very thorough explanation.
     
  10. Styxx

    Styxx Banned

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    Thanks for sharing WhitPhil, I never in 10 years had any problem with ScanDisk and I won't start crying "the sky is falling" just off one (1) poster's first person and second-hand reports. Again, tnx 4 sharing anyway.

    Post unsubscribed.

    Bye.
     
  11. bilnrobn

    bilnrobn Thread Starter

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    Differing opinions are good. They give a broader understanding of all sides of the question. They certainly did in this case. Thanks guys!
     
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