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UWF on Windows 10 IoT Enterprise

    Question

  • My problem is on Windows 10 IoT Enterprise, but I can not find a better forum for this.

    After Enabling UWF and excluding a folder, when I copy files in the excluded folder the overlay decreases of he same amount !!With this behaviour, UWF with exclusion becomes useless!!

    Here are the steps to easly reproduce the problem:

    In VirtualBox create a VM -->
    - Windows 10 x64;
    - Disks: 50Gb + 14GB
    - ISO: en_windows_10_enterprise_2015_ltsb_x64_dvd_6848446.iso
    - Guest Additions

    Enable UWF and reboot

    uwfmgr volume protect c:
    uwfmgr filter enable
    uwfmgr file Add-Exclusion c:\beps
    In c:\beps copy a file (I copied an MP4 35Mb)
    __________________________________________________
    C:\Windows\system32>uwfmgr get-config
    Unified Write Filter Configuration Utility version 10.0.10240
    Copyright (C) Microsoft Corporation. All rights reserved.

    Current Session Settings
    FILTER SETTINGS
        Filter state:    OFF
        Pending commit:  N/A
        Shutdown pending:No
    SERVICING SETTINGS
        Servicing State: OFF
    OVERLAY SETTINGS
        Type:               RAM
        Maximum size:       1024 MB
        Warning Threshold:  512 MB
        Critical Threshold: 1024 MB
    VOLUME SETTINGS
        *** No volumes configured
    REGISTRY EXCLUSIONS
        *** No exclusions
    ____________________
    Next Session Settings
    FILTER SETTINGS
        Filter state:    ON
        Pending commit:  N/A
    SERVICING SETTINGS
        Servicing State: OFF
    OVERLAY SETTINGS
        Type:               RAM
        Maximum size:       1024 MB
        Warning Threshold:  512 MB
        Critical Threshold: 1024 MB
    VOLUME SETTINGS
    Volume 514fd46f-0000-0000-0000-501f00000000 [C:]
        Volume state:     Protected
        Volume ID:        514fd46f-0000-0000-0000-501f00000000

        File Exclusions:
    Next Session Exclusions for Volume 514fd46f-0000-0000-0000-501f00000000 [C:]
        C:\beps
    REGISTRY EXCLUSIONS
        *** No exclusions
    C:\Windows\system32>

    ------- After reboot the time to display these lines is longer than usual!! ----------
    Microsoft Windows [Version 10.0.10240]
    (c) 2015 Microsoft Corporation. All rights reserved.

    C:\Windows\system32>uwfmgr get-config
    Unified Write Filter Configuration Utility version 10.0.10240
    Copyright (C) Microsoft Corporation. All rights reserved.

    Current Session Settings
    FILTER SETTINGS
        Filter state:    ON
        Pending commit:  N/A
        Shutdown pending:No
    SERVICING SETTINGS
        Servicing State: OFF
    OVERLAY SETTINGS
        Type:               RAM
        Maximum size:       1024 MB
        Warning Threshold:  512 MB
        Critical Threshold: 1024 MB
    VOLUME SETTINGS
    Volume 514fd46f-0000-0000-0000-501f00000000 [C:]
        Volume state:     Protected
        Volume ID:        514fd46f-0000-0000-0000-501f00000000
    ___
        File Exclusions:
    Current Session Exclusions for Volume 514fd46f-0000-0000-0000-501f00000000 [C:]
        C:\beps
    REGISTRY EXCLUSIONS
        *** No exclusions
    Next Session Settings
    FILTER SETTINGS
        Filter state:    ON
        Pending commit:  N/A
    SERVICING SETTINGS
        Servicing State: OFF
    OVERLAY SETTINGS
        Type:               RAM
        Maximum size:       1024 MB
        Warning Threshold:  512 MB
        Critical Threshold: 1024 MB
    VOLUME SETTINGS
    Volume 514fd46f-0000-0000-0000-501f00000000 [C:]
        Volume state:     Protected
        Volume ID:        514fd46f-0000-0000-0000-501f00000000
        File Exclusions:
    Next Session Exclusions for Volume 514fd46f-0000-0000-0000-501f00000000 [C:]
        C:\beps
    REGISTRY EXCLUSIONS
        *** No exclusions
    ___________________________
    C:\Windows\system32>uwfmgr overlay get-availablespace
    The overlay has 1003 MB available space.

    Lets copy the mp4 file for ten times (35Mb * 10)

    c:\Windows\system32>uwfmgr overlay get-availablespace
    The overlay has 692 MB available space.

    Lets duplicate the mp4 files(384Mb) in c:\beps folder
    NOTE: c:\beps folder is excluded from the filter!!

    C:\Windows\system32>uwfmgr overlay get-availablespace
    The overlay has 317 MB available space.

    Lets duplicate the mp4 files(22*34Mb =748Mb ) in c:\beps folder:
    The copy locked-down after 17 files and the system remain in idle!!
    Refer to snap-shot

    C:\Windows\system32>uwfmgr overlay get-availablespace
    The overlay has 0 MB available space.

    C:\Windows\system32>time
    The current time is: 19:01:04,27
    Enter the new time:
    From Task manager "explorer is still working, but it seams locked"
    C:\Windows\system32>shutdown -r -t 0
    (restart anyway)
    After 50 minutes is still in "restarting" !!
    After killing the VM, the situation is this:
    - In the c:\beps folder there are 40 items istead of 44 expected.
    - 34 of them are corrected and the last 6 are corrupted !!

    C:\Windows\system32>uwfmgr overlay get-availablespace
    The overlay has 995 MB available space.

    __________________________________________________

    Is there any exclusion to do to avoid this problem?

     


    Beppe Platania Windows Embedded MVP http://blog.bepseng.it

    Sunday, June 19, 2016 9:20 PM

Answers

  • This is a known issue with UWF. Here is a comment from WES8/WEI8.1 from https://msdn.microsoft.com/en-us/library/jj979700(v=winembedded.81).aspx

    -------------------------------------

    For WE8S (and WE8I), the following actions and events add to overlay usage:

    • Changes and deletions in excluded directories, excluded files, or excluded registry items.
    • File and registry commits.

    ------------------------------------

    The overlay is always getting filled, even writing to an excluded directory. Try rebooting the system and see if you get the memory back.


    Sean Liming - Book Author: Starter Guide SIM (WEI), Pro Guide to WE8S & WES 7, Pro Guide to POS for .NET - www.annabooks.com / www.seanliming.com

    Monday, June 20, 2016 2:18 PM
    Moderator
  • UWF has always worked this way since it was released in WES8. The problem is that few used WES8 or WE8.1I to notice the quirk. If you have a big database to save, the recommended solution is to store data on a second partition.

    Sean Liming - Book Author: Starter Guide SIM (WEI), Pro Guide to WE8S & WES 7, Pro Guide to POS for .NET - www.annabooks.com / www.seanliming.com

    Thursday, September 8, 2016 5:07 PM
    Moderator

All replies

  • This is a known issue with UWF. Here is a comment from WES8/WEI8.1 from https://msdn.microsoft.com/en-us/library/jj979700(v=winembedded.81).aspx

    -------------------------------------

    For WE8S (and WE8I), the following actions and events add to overlay usage:

    • Changes and deletions in excluded directories, excluded files, or excluded registry items.
    • File and registry commits.

    ------------------------------------

    The overlay is always getting filled, even writing to an excluded directory. Try rebooting the system and see if you get the memory back.


    Sean Liming - Book Author: Starter Guide SIM (WEI), Pro Guide to WE8S & WES 7, Pro Guide to POS for .NET - www.annabooks.com / www.seanliming.com

    Monday, June 20, 2016 2:18 PM
    Moderator
  • Were you able to verify that the issue was by design?

    Sean Liming - Book Author: Starter Guide SIM (WEI), Pro Guide to WE8S & WES 7, Pro Guide to POS for .NET - www.annabooks.com / www.seanliming.com

    Sunday, June 26, 2016 12:27 AM
    Moderator
  • After rebooting I get the memory back.

    If this issue is by design the UWF becomes useless ! 


    Beppe Platania Windows Embedded MVP http://blog.bepseng.it

    Monday, June 27, 2016 7:20 AM
  • Yes, that appears to be the case. Bad design. I think they tried to solve one issue, but created another. The only work around is to track that the overlay is getting full and perform a reboot.

    Sean Liming - Book Author: Starter Guide SIM (WEI), Pro Guide to WE8S & WES 7, Pro Guide to POS for .NET - www.annabooks.com / www.seanliming.com

    Monday, June 27, 2016 3:44 PM
    Moderator
  • Oh ... great.

    Are we going to see a fix for this, because that is staggeringly numb.


    =^x^=

    Wednesday, June 29, 2016 11:26 PM
  • Contact your local Microsoft representative and feedback your concern :)


    Sean Liming - Book Author: Starter Guide SIM (WEI), Pro Guide to WE8S & WES 7, Pro Guide to POS for .NET - www.annabooks.com / www.seanliming.com

    Thursday, June 30, 2016 4:14 AM
    Moderator
  • Just out of interest, does anyone know what the rationale behind making the write protection layer work like this? Microsoft must have a reason for it - but I can't fathom what that reason might be.

    I can't understand why it would be a good idea to consume the write protection overlay with records of actions that the user clearly wanted to take place or they wouldn't have created the write exemption in the first place.

    Maybe I'm missing something. I'd just like to understand a scenario where this is correct functionality. I've just asked an identical question to this one on the forum (I hadn't spotted this post before I submitted it). The way things stand with this functionality - Windows 10 is useless to my application. I need to create temporary data in an excluded folder. This worked fine in Windows 7 Embedded but (IMHO) is broken in Windows 10 LTSB

    Tuesday, September 6, 2016 1:41 PM
  • Not sure why they architected in this way.  Maybe as a shortcut to get the filter done.

    The issue has been raised to them to see if a new version can be created. Don't hold your breath.

    I suggest you raise the issue to a Microsoft distributor or technical contact so more data points can be collected.


    Sean Liming - Book Author: Starter Guide SIM (WEI), Pro Guide to WE8S & WES 7, Pro Guide to POS for .NET - www.annabooks.com / www.seanliming.com

    Tuesday, September 6, 2016 4:15 PM
    Moderator
  • Is it still in the 2016 LTSB?

    I just got my kit and I'm not looking forward to it.


    =^x^=

    Wednesday, September 7, 2016 12:53 AM
  • Yes it is I'm afraid - that was where I first discovered the problem as 2016 LTSB was the first version I downloaded from MSDN

    I honestly can't think of any situation where is is considered reasonable behaviour to chew up a resource to the point that will grind the machine to a halt during normal operation. It seems like madness to me and will prevent me from migrating from WES7 to Windows 10 for my product.

    I do hope someone from Microsoft is reading this. If so, can we have the option for writes to a folder (that is excluded from the write filter layer) to NOT consume the write cache?

    Alternatively, is there a way of dynamically cleaning out the write cache without having to reboot the machine? In my application, these industrial devices sit out on the network collecting data 24x7x365 and cannot be routinely rebooted (or grind to a halt).

    Wednesday, September 7, 2016 7:03 AM
  • UWF has always worked this way since it was released in WES8. The problem is that few used WES8 or WE8.1I to notice the quirk. If you have a big database to save, the recommended solution is to store data on a second partition.

    Sean Liming - Book Author: Starter Guide SIM (WEI), Pro Guide to WE8S & WES 7, Pro Guide to POS for .NET - www.annabooks.com / www.seanliming.com

    Thursday, September 8, 2016 5:07 PM
    Moderator
  • I don't understand how this can be considered correct (or answered). 

    How can it be normal that (for example) logfiles that exist on the protected volume (but are in the exclusion list) consume resources from the write protection layer - ultimately causing the machine to fall over.

    Please can someone tell me of one single situation where it would be a good idea to consume resources in normal operation. If we were talking about a program here, we would say that the program had a memory leak that needs fixing.
    Could someone explain why the WES7 functionality was considered incorrect - so much so that Microsoft felt the need to change it to how it works now?

    To my mind, this is monumentally broken and will absolutely prevent me from migrating from WES7 to Windows 10 - our customers simply will not accept having to routinely reboot the device as an option. :o(

    Tuesday, October 25, 2016 7:25 AM
  • The little quirk is not considered normal. It is a disappointing side effect of the new UWF. Until Microsoft can fix this quirk, the work around is all we have.

    Please feedback to Microsoft directly. The more developers that provide feedback the better.


    Sean Liming - Book Author: Starter Guide SIM - www.annabooks.com / www.seanliming.com

    Tuesday, October 25, 2016 4:22 PM
    Moderator
  • Same issue here!

    Please fix Microsoft.

    In this state we can not use UWF!

    Friday, January 19, 2018 1:37 PM