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How can I disable NTFS write-caching for external drives? RRS feed

  • Question

  • I want to disable write-caching for external NTFS drives as a (likely) workaround for the data corruption/alteration issue that is occurring intermittently on large file transfers (see thread http://social.technet.microsoft.com/Forums/en-US/w7itproperf/thread/13a7426e-1a5d-41b0-9e16-19437697f62b ).    Is there a registry setting for doing so?

    Thank you.

    -Kipp

    Thursday, January 26, 2012 8:03 PM

Answers

  •  

    They probably mean that the write happens immediately, but that a subsequent read of that data would come out of the cache rather than from the drive hardware itself.

     

    -Noel


    Detailed how-to in my new eBook: Configure The Windows 7 "To Work" Options

    It means what it says...that the data passes "through" the cache but only briefly.    Please research "write-through" caching per Microsoft's own technical descriptions, and please cease the speculation that is inconsistent with specific information provided by Microsoft.

    To repeat, this behavior of "write-through" caching is also documented at http://msdn.microsoft.com/en-us/library/windows/desktop/aa364218%28v=vs.85%29.aspx

    "With write-through caching enabled, data is still written into the cache, but the cache manager writes the data immediately to disk rather than incurring a delay by using the lazy writer."



    • Marked as answer by KT-Retro Friday, February 3, 2012 2:43 PM
    • Edited by KT-Retro Friday, February 3, 2012 2:44 PM
    Friday, February 3, 2012 2:29 PM

All replies

  • Doesn't the Removal policy setting Quick removal do just that?  I thought you mentioned that in your other thread.

     

     

    -Noel


    Detailed how-to in my new eBook: Configure The Windows 7 "To Work" Options

    • Marked as answer by Juke Chou Friday, February 3, 2012 6:12 AM
    • Unmarked as answer by KT-Retro Friday, February 3, 2012 2:27 PM
    Thursday, January 26, 2012 11:32 PM
  • Doesn't the Removal policy setting Quick removal do just that?  I thought you mentioned that in your other thread.

     

     

    -Noel


    Detailed how-to in my new eBook: Configure The Windows 7 "To Work" Options

     

    Based on what I've read, Quick Removal does not completely disable it...but it instead causes the OS to make only minimal use of the cache.

    Thursday, January 26, 2012 11:38 PM
  • Hi,

    It indeed disables write caching.


    Juke Chou

    TechNet Community Support

    • Marked as answer by Juke Chou Friday, February 3, 2012 6:12 AM
    • Unmarked as answer by KT-Retro Friday, February 3, 2012 2:27 PM
    Tuesday, January 31, 2012 9:37 AM
  • Hi,

    It indeed disables write caching.


    Juke Chou

    TechNet Community Support

    According to http://www.windows7library.com/blog/performance/usb-quick-removal-option, it's not 100% disabled in Quick Removal mode under Windows 7:

    "In this mode the device operates on write commands as if there were no cache. The cache may still provide a small performance benefit but the main priority is to safeguard data."

    This behavior of "write-through" caching is also documented at http://msdn.microsoft.com/en-us/library/windows/desktop/aa364218%28v=vs.85%29.aspx

    "With write-through caching enabled, data is still written into the cache, but the cache manager writes the data immediately to disk rather than incurring a delay by using the lazy writer."


    • Edited by KT-Retro Tuesday, January 31, 2012 6:18 PM
    Tuesday, January 31, 2012 6:15 PM
  • They probably mean that the write happens immediately, but that a subsequent read of that data would come out of the cache rather than from the drive hardware itself.

     

    -Noel


    Detailed how-to in my new eBook: Configure The Windows 7 "To Work" Options

    • Marked as answer by Juke Chou Friday, February 3, 2012 6:12 AM
    • Unmarked as answer by KT-Retro Friday, February 3, 2012 2:27 PM
    Wednesday, February 1, 2012 12:46 AM
  •  

    They probably mean that the write happens immediately, but that a subsequent read of that data would come out of the cache rather than from the drive hardware itself.

     

    -Noel


    Detailed how-to in my new eBook: Configure The Windows 7 "To Work" Options

    It means what it says...that the data passes "through" the cache but only briefly.    Please research "write-through" caching per Microsoft's own technical descriptions, and please cease the speculation that is inconsistent with specific information provided by Microsoft.

    To repeat, this behavior of "write-through" caching is also documented at http://msdn.microsoft.com/en-us/library/windows/desktop/aa364218%28v=vs.85%29.aspx

    "With write-through caching enabled, data is still written into the cache, but the cache manager writes the data immediately to disk rather than incurring a delay by using the lazy writer."



    • Marked as answer by KT-Retro Friday, February 3, 2012 2:43 PM
    • Edited by KT-Retro Friday, February 3, 2012 2:44 PM
    Friday, February 3, 2012 2:29 PM
  • Hi,

    It indeed disables write caching.


    Juke Chou

    TechNet Community Support


    Please do not mark as an answer, as this is incorrect.
    Friday, February 3, 2012 2:45 PM
  • What it says is consistent with what I said (and I did read about it before answering).  I'm sorry I tried to oversimplify an explanation for you of why they would want to make it work as it does.

    Since Windows is a proprietary implementation, all we can do is make theories (speculate) then test them.

    Good luck with your problem.

     

    -Noel


    Detailed how-to in my new eBook: Configure The Windows 7 "To Work" Options

    Friday, February 3, 2012 3:19 PM