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iSCSI - Disable Nagle

    Întrebare

  • Hello,

    I've been looking at iSCSI performance tuning for our R2 Hyper-V machines with 10Gbe NICs.  There have been a couple of references in some PowerPoints to the following registry key:

     HKLM\SYSTEM\CurrentControlSet\Control\Class\{4D36E97B-E325-11CE-BFC1-08002BE10318}\<Instance Number>\Parameters\iSCSIDisableNagle

    I know it will have to be created.  What I don't know is if that is a key, DWORD and what value needs to be assigned, or something else.  Also, I'm guessing a restart is required for this to take effect, but not sure.  Can someone help me out with finding the correct information for this?

    Thanks,

    Kevin

    4 ianuarie 2012 18:29

Răspunsuri

  • Please follow the below links... for better understanding of Microsoft iSCSI Software Initiator

    Disable Nagle within the iSCSI Initiator :  tcp-nodelay=1

    http://myqtest.blogspot.com/2009/11/nagle-algorithm.html

    http://download.microsoft.com/download/A/E/9/AE91DEA1-66D9-417C-ADE4-92D824B871AF/uGuide.doc

     

    Hope it Helps.... what ur looking for..


    Gopi Kiran ------------------------------- This posting is provided AS-IS with no warranties/guarantees and confers no rights.
    4 ianuarie 2012 20:55

Toate mesajele

  • Please follow the below links... for better understanding of Microsoft iSCSI Software Initiator

    Disable Nagle within the iSCSI Initiator :  tcp-nodelay=1

    http://myqtest.blogspot.com/2009/11/nagle-algorithm.html

    http://download.microsoft.com/download/A/E/9/AE91DEA1-66D9-417C-ADE4-92D824B871AF/uGuide.doc

     

    Hope it Helps.... what ur looking for..


    Gopi Kiran ------------------------------- This posting is provided AS-IS with no warranties/guarantees and confers no rights.
    4 ianuarie 2012 20:55
  • Gopi,

    Thank you, but I what I need to know is the correct way to set the registy setting referenced in my post.  I can't find any documentation outside of PowerPoints from Microsoft, but it's not clear to me if it's a DWORD, a key, etc.

    Kevin

    4 ianuarie 2012 21:42
  • Kevin,

    Its a DWORD (boolean)

    please refer this link :http://msdn.microsoft.com/en-us/library/windows/desktop/ms738596%28v=vs.85%29.aspx


    Gopi Kiran
    5 ianuarie 2012 10:51
  • Hello,

    I've been looking at iSCSI performance tuning for our R2 Hyper-V machines with 10Gbe NICs.  There have been a couple of references in some PowerPoints to the following registry key:

     HKLM\SYSTEM\CurrentControlSet\Control\Class\{4D36E97B-E325-11CE-BFC1-08002BE10318}\<Instance Number>\Parameters\iSCSIDisableNagle

    I know it will have to be created.  What I don't know is if that is a key, DWORD and what value needs to be assigned, or something else.  Also, I'm guessing a restart is required for this to take effect, but not sure.  Can someone help me out with finding the correct information for this?

    Thanks,

    Kevin

    Kevin,

    there are quite a lot of other settings except Nagle (TCP window size, Jumbo frame size, delayed ACK etc) to play with. Take a look at this page it's hosted on StarWind site but these tweaks affect all of Windows based iSCSI software:

    http://www.starwindsoftware.com/forums/starwind-f5/recommended-tcp-settings-t2293.html

    Make sure you apply them correctly (most of them require reboot) and also grab NTtcp and IPerf to measure TCP stack performance *BEFORE* and *AFTER* our mods.

    Good luck! :)

    -nismo

    7 ianuarie 2012 05:39
  • Everyone,

    Thanks for the replies!  I still can't find an example anywhere of that registry entry.  It's supposedly in an EMC kb article, but I don't have access to that.  I'm going apply the other suggestions, and create a DWORD iSCSIDisableNagle=1 and see what happens.

     

    Kevin

    8 ianuarie 2012 16:21
  • Everyone,

    Thanks for the replies!  I still can't find an example anywhere of that registry entry.  It's supposedly in an EMC kb article, but I don't have access to that.  I'm going apply the other suggestions, and create a DWORD iSCSIDisableNagle=1 and see what happens.

     

    Kevin

    I think nothing is going to happen. BTW, all software iSCSI targets and initiators I know do disable Nagle themselves.

    -nismo

    9 ianuarie 2012 15:24
  • nismo,

    You'd think so, but this is specifically referenced in Microsoft presentations as an option, and there are posts all over about setting TcpAckFrequency=1 one as well. I still just wish I could find a reference on how to actually set this key.  I suppose we'll open a case with Microsoft...

    Thanks again, everyone.

    20 februarie 2012 16:50