File transfers from iMac to Windows Share on another computer. Very slow!

Discussion in 'iMac' started by JoshFink, Oct 31, 2007.

  1. JoshFink macrumors regular

    Joined:
    Aug 3, 2007
    Location:
    Atlanta, GA
    #1
    Hopefully someone has some ideas on how best to troubleshoot this.

    I have an iMac and a Windows 2003 File Server.

    The iMac sits on a gigabit switch with another computer, an XP machine and the 2003 File Server sits on another gigabit switch.

    The problem I'm having is that transfers from the iMac to the 2003 File Server are very slow whereas from the XP machine on the same switch they are fast.

    Any ideas on how to test this or how I might fix the problem?

    The Network interface itself is set to:
    1000baseT
    full-duplex
    MTU: standard (1500)

    I've tried it with both full-duplex and full-duplex (flow control).

    The directory I'm transfering is a 7.56gb directory and it's taking over an hour to transfer.

    Thanks

    Josh
     
  2. raffinux macrumors newbie

    Joined:
    Jul 12, 2007
    #2
    Hi,

    I would personally start Ethereal on the server and on the client and take a sniff of the traffic (some minutes should be enough) in both cases: fast and slow one. Then I would compare the traces.

    You can find many many thing such as missed ACK, retransmission, TCP windowing problem etc. Some of this problem can be due to configuration issues, some other to hardware problems such as bad cable, bad switch port etc.

    Good luck!
     
  3. JoshFink thread starter macrumors regular

    Joined:
    Aug 3, 2007
    Location:
    Atlanta, GA
    #3
    I've never used Ethereal. How easy is it for a basic user with no real knowledge of packet sniffing?

    Thanks

    Josh
     
  4. JoshFink thread starter macrumors regular

    Joined:
    Aug 3, 2007
    Location:
    Atlanta, GA
    #4
    While searching, I found this post. It seems to help

    1. disabled IPv6 on Mac OS X (System Preferences->Network->Configure->Configure IPv6->Off)

    2. uninstalled ipv6 on Windows XP via command line: netsh interface ipv6 uninstall
    3. on MAC OS X, set ACK no delay by addingto you /etc/smb.conf file (sudo vi /etc/smb.conf):

    socket options = TCP_NODELAY IPTOS_LOWDELAY file.

    I found it here : http://echeng.com/journal/2006/09/13/mac-os-x-slow-network-performance-to-windows-xp/

    Instead of the transfer taking over an hour, it took 18 minutes. Huge difference
     

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