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File size reported reported differently RRS feed

  • Question

  • Can someone help me explain why this file size is reported differently depending whether you list file or folder properties:

    This is an Azure Basic_A1 VM. Drive E: is standard VHD attached to the VM (Page Block Storage).

    This is an active/open file that is currently being written to, and is growing in size.

    How is it that file size is reported as 8 GB if you query the folder, and 24 GB if you query the file?



    Sam Boutros, Senior Consultant, Software Logic, KOP, PA http://superwidgets.wordpress.com (Please take a moment to Vote as Helpful and/or Mark as Answer, where applicable) _________________________________________________________________________________ Powershell: Learn it before it's an emergency http://technet.microsoft.com/en-us/scriptcenter/powershell.aspx http://technet.microsoft.com/en-us/scriptcenter/dd793612.aspx



    • Edited by Sam Boutros Tuesday, September 23, 2014 10:25 AM
    Tuesday, September 23, 2014 10:23 AM

All replies

  • Hello Sam,

    Thanks for posting here!

    As per the description provided what I have understood is that it could be an issue with the file system.

    .Vbk extension seems to be related to backup but not sure.

    I would want more information about the issue for better understanding.

    You might want to check the below mentioned links

    http://helpcenter.veeam.com/backup/70/vsphere/index.html?retention_deleted_vms.html

    http://forums.veeam.com/veeam-backup-replication-f2/question-about-vbk-vrb-vbm-file-s-and-offsite-backups-t15741.html

    Hope this helps!

    Best Regards,

    Sadiqh Ahmed

    Disclaimer: This response contains a reference to a third party World Wide Web site.
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    There are inherent dangers in the use of any software found on the Internet, and Microsoft cautions you to make sure that you completely understand the risk before retrieving any software from the Internet.

    Tuesday, September 23, 2014 2:35 PM
  • Is there specific information you're asking for?

    Sam Boutros, Senior Consultant, Software Logic, KOP, PA http://superwidgets.wordpress.com (Please take a moment to Vote as Helpful and/or Mark as Answer, where applicable) _________________________________________________________________________________ Powershell: Learn it before it's an emergency http://technet.microsoft.com/en-us/scriptcenter/powershell.aspx http://technet.microsoft.com/en-us/scriptcenter/dd793612.aspx

    Tuesday, September 23, 2014 6:48 PM
  • The upload is still in progress. I'm running this script periodically:

    $Folder = "e:\Backups\Sam Client\To Azure Page Block Repository"
    Write-Host "File size reported from file list:   $('{0:N2}' -f ((dir "$Folder\To Azure Page Block Repository2014-09-23T051450.vbk").length/1GB)) GB" -ForegroundColor Green
    Write-Host "File size reported from folder List: $('{0:N2}' -f ((dir $Folder)[1].length/1GB)) GB" -ForegroundColor Yellow
    dir $Folder | FT -AutoSize

    File size continues to show different sizes:


    Sam Boutros, Senior Consultant, Software Logic, KOP, PA http://superwidgets.wordpress.com (Please take a moment to Vote as Helpful and/or Mark as Answer, where applicable) _________________________________________________________________________________ Powershell: Learn it before it's an emergency http://technet.microsoft.com/en-us/scriptcenter/powershell.aspx http://technet.microsoft.com/en-us/scriptcenter/dd793612.aspx

    Tuesday, September 23, 2014 7:55 PM
  • I ran this script for the last 8 or so hours out of this 19 hour upload:

    $Folder = "e:\Backups\Sam Client\To Azure Page Block Repository"
    $Log = "c:\Sandbox\Upload4.csv"
    Write-Output '"FileQuery","FolderQuery","Time"' | Out-File $Log 
    
    Do {
        $a = (dir "$Folder\To Azure Page Block Repository2014-09-23T051450.vbk").length/1GB
        $b = (dir $Folder)[1].length/1GB
    
        cls
        Write-Host "File size reported from file list:   $('{0:N2}' -f $a) GB" -ForegroundColor Green
        Write-Host "File size reported from folder list: $('{0:N2}' -f $b) GB" -ForegroundColor Yellow
        dir $Folder | FT -AutoSize
        
        Write-Output """$a"",""$b"",""$(Get-Date -Format 'hh:mm:ss tt')""" | Out-File $Log -Append
        Start-Sleep -Seconds 10
    
    } while ($a -ne $b)

    That collected over 3,000 sampling points that are 10 seconds apart. I then graphed that data:

    The vertical axis is file size in GB, the horizontal axis is time (not directly - it's sampling points)

    And you can see file size as reported by folder query lags behind file size as reported by file query. The amount of lag was upwards of 90GB at its highest point. And it took anywhere from roughly 5 minutes to 3 hours for 1 indicator to catch up with the other. 

    The question is why these two sets of numbers are different? Is there caching going on somewhere? Is one indicator accounting for all file blocks while the other is accounting for committed blocks only? Can someone from Microsoft shed some light on this? This is important to know to be able to plan disk space requirements when attempting to use Azure as backup target with large data sets regardless of the software used.


    Sam Boutros, Senior Consultant, Software Logic, KOP, PA http://superwidgets.wordpress.com (Please take a moment to Vote as Helpful and/or Mark as Answer, where applicable) _________________________________________________________________________________ Powershell: Learn it before it's an emergency http://technet.microsoft.com/en-us/scriptcenter/powershell.aspx http://technet.microsoft.com/en-us/scriptcenter/dd793612.aspx





    • Edited by Sam Boutros Wednesday, September 24, 2014 4:51 PM
    Wednesday, September 24, 2014 10:08 AM
  • Hello Sam,

    Thank you for your response.

    I reproduced the issue and it works fine for me.

    I would want some more details from you.

    How do you create a .VBK file, Is that you're running a backup of a VM using a third party backup solution?

    How do you upload it?

    Best Regards,

    Sadiqh Ahmed

    Thursday, October 2, 2014 1:48 PM
  • Hello Sam,

    I hope the issue is resolved.

    If the issue still persist let us know so that we can assist you further.

    Best Regards,

    Sadiqh Ahmed

    Please remember to click “Mark as Answer” on the post that helps you, and to click “Unmark as Answer” if a marked post does not actually answer your question. This can be beneficial to other community members reading the thread.

    Thursday, October 9, 2014 4:31 PM
  • Hello Sam,

    I hope the issue is resolved.

    If the issue still persist let us know so that we can assist you further.

    Best Regards,

    Sadiqh Ahmed

    Please remember to click “Mark as Answer” on the post that helps you, and to click “Unmark as Answer” if a marked post does not actually answer your question. This can be beneficial to other community members reading the thread.

    Issue is not resolved. You have not participated any helpful information or comments to this issue. Please escalate to someone who knows better.

    Thank you.


    Sam Boutros, Senior Consultant, Software Logic, KOP, PA http://superwidgets.wordpress.com (Please take a moment to Vote as Helpful and/or Mark as Answer, where applicable) _________________________________________________________________________________ Powershell: Learn it before it's an emergency http://technet.microsoft.com/en-us/scriptcenter/powershell.aspx http://technet.microsoft.com/en-us/scriptcenter/dd793612.aspx

    Thursday, October 9, 2014 4:39 PM
  • Hi Sam,

    Please let me know some detailed information

    1. What's the OS version of the affected server?

    2. will it show the same result if we use command line not powershell?

    3. What's the size of this file if we check its properties?

    4. has any other file experienced the same issue? or just this one?

    5. Since .vbk file is related to 3rd party software, have you involved the vendor to verify if there's any comments?

    Best Regards,


    Please remember to click “Mark as Answer” on the post that helps you, and to click “Unmark as Answer” if a marked post does not actually answer your question. This can be beneficial to other community members reading the thread.

    Saturday, November 8, 2014 6:19 AM
  • May I know the above information? I'd like to have a further understanding of the issue.

    Please remember to click “Mark as Answer” on the post that helps you, and to click “Unmark as Answer” if a marked post does not actually answer your question. This can be beneficial to other community members reading the thread.

    Thursday, November 20, 2014 10:33 AM
  • Hi Sam,

    Please let me know some detailed information

    1. What's the OS version of the affected server?

    2. will it show the same result if we use command line not powershell?

    3. What's the size of this file if we check its properties?

    4. has any other file experienced the same issue? or just this one?

    5. Since .vbk file is related to 3rd party software, have you involved the vendor to verify if there's any comments?

    Best Regards,


    Please remember to click “Mark as Answer” on the post that helps you, and to click “Unmark as Answer” if a marked post does not actually answer your question. This can be beneficial to other community members reading the thread.

    1. Windows Server 2012 R2 DataCenter
    2. Not attempted. Can you reproduce?
    3. Not Attempted. As mentioned above file was open and growing in size for hours. Can you reproduce?
    4. Yes. Issue can be reproduced consistently.
    5. No. Isue is not related to file type or content. The question is about Windows native tools inconsistencies in reporting open file size.

    Sam Boutros, Senior Consultant, Software Logic, KOP, PA http://superwidgets.wordpress.com (Please take a moment to Vote as Helpful and/or Mark as Answer, where applicable) _________________________________________________________________________________ Powershell: Learn it before it's an emergency http://technet.microsoft.com/en-us/scriptcenter/powershell.aspx http://technet.microsoft.com/en-us/scriptcenter/dd793612.aspx

    Thursday, November 20, 2014 12:39 PM
  • I'd like to say that I cannot reproduce this issue in my lab as I don't have such types of files, for these questions, I wanted to have a further understanding of this issue. tomorrow I'll be available to do some tests in my lab to try to reproduce the issue, will let you know the result ASAP

    Please remember to click “Mark as Answer” on the post that helps you, and to click “Unmark as Answer” if a marked post does not actually answer your question. This can be beneficial to other community members reading the thread.

    Wednesday, November 26, 2014 11:23 AM
  • I will go on doing a test tomorrow morning, and there should be an update tomorrow.

    Please remember to click “Mark as Answer” on the post that helps you, and to click “Unmark as Answer” if a marked post does not actually answer your question. This can be beneficial to other community members reading the thread.

    Friday, December 5, 2014 10:23 AM
  • did a test:

    1. I'm applying some hotfixes, so the size of CBS.log should be growing. Run dir to check the size both from folder and the filz it self, found the same size. this means that DIR commands should not report open file size. our issue may be caused by the Writing mechanism of the VBK file.

    2. Since the it may be caused by the DIR commands, I'd like to confirm if you can reproduce on another type of file (maybe CBS.log) on this server, or the VBK files on another server?

    3. I have done some research, this should not be a known issue, what we want to test now is to involve the 3rd party vendor to check the Writing mechanism of this software, this may bring some help for us.

    Best Regards,

    Sophia


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    Saturday, December 6, 2014 7:52 AM
  • Hi,

    Could you please let me know if you have done a test for CBS.log when applying patches? did the DIR commands show a different log size from the folder and the file itself?

    as we mentioned, if the size is same, we may need to involve 3rd party software to work with us to try to reach out the possible causes. maybe the Writing mechanism caused this issue.

    Best Regards,

    Sophia


    Please remember to click “Mark as Answer” on the post that helps you, and to click “Unmark as Answer” if a marked post does not actually answer your question. This can be beneficial to other community members reading the thread.

    Friday, December 12, 2014 2:05 AM
  • Sophia,

    It may take me a few days to test and get back to you..

    Sam


    Sam Boutros, Senior Consultant, Software Logic, KOP, PA http://superwidgets.wordpress.com (Please take a moment to Vote as Helpful and/or Mark as Answer, where applicable) _________________________________________________________________________________ Powershell: Learn it before it's an emergency http://technet.microsoft.com/en-us/scriptcenter/powershell.aspx http://technet.microsoft.com/en-us/scriptcenter/dd793612.aspx

    Friday, December 12, 2014 8:08 AM
  • Hi Sam,

    Have you taken some time to do a test fro CBS.log? and could you pelase let me know if you reproduced this issue on CBS.log when you are available?

    Thnaks for your time.

    Regards,

    Sophia


    Please remember to click “Mark as Answer” on the post that helps you, and to click “Unmark as Answer” if a marked post does not actually answer your question. This can be beneficial to other community members reading the thread.

    Tuesday, December 16, 2014 9:52 AM