1gbps between 2 Windows Servers

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This topic contains 12 replies, has 4 voices, and was last updated by Avatar ikon 11 years, 1 month ago.

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    ikon
    Member
    #139687

    Hey guys

    I have recently purchased a Lacie Ethernet Disk 2TB (1Gbps ethernet card), im using a Windows Server 2003 Enterprise Edition OS on A HP Proliant DL580 with SAS 15k RPM Drives.

    I have put a CAT5e cable between the 2, the cable has printed accross is tested for Gigabit ethernet, i have IP communication between the two.

    I have a scirpt that does an xcopy of some VMware images from the Windows Server to the Lacie Ethernet Disk.

    for some reason i am only getting 15% bandwith usage, using some bandwidth monitoring software i can see im getting 120Mbps throughput, i understand the bottle necks and im not going to recieve a full 1000mpbs but i would of expected at least 400mbps??

    Any ideas?

    Avatar
    L4ndy
    Member
    #275427

    Re: 1gbps between 2 Windows Servers

    Hi Ikon,

    Have you tried disabling any AV and Firewall as per this: http://www.lacie.com/uk/support/support_manifest.htm?id=10159&article=1133

    Ta

    Avatar
    ikon
    Member
    #354202

    Re: 1gbps between 2 Windows Servers

    Hi

    Thanks for taking the time to look that up.

    Yes i have tried disabling and uninstalling Sophos, there is no firewall on at the moment.

    the script is running at the moment @ 95mbps, the only thing i can think of is that the Host machine that is running 4 virtual machines is the server that is copying the images, they are on right now and being accessed, so maybe i will try an out of hours copy.

    But im not totally convinced.

    Avatar
    Dumber
    Participant
    #199803

    Re: 1gbps between 2 Windows Servers

    bites or bytes?
    are the servers switched?

    Please review:
    http://support.microsoft.com/kb/Q93444
    http://support.microsoft.com/kb/Q172983

    Avatar
    ikon
    Member
    #354203

    Re: 1gbps between 2 Windows Servers

    Dumber;152148 wrote:
    bites or bytes?
    quote]

    bits per second not Bytes.

    It is a cat5e cable between 2 devices both with 1Gbps Network cards.

    Thanks ill check those links

    ive done some searching, and seems like thise is very similar to my prob, i will also try this from the following link

    http://forums.techarena.in/server-networking/922765.htm

    I will let you know the outcome, thanks for the help so far.

    Cheers

    Avatar
    Dumber
    Participant
    #199804

    Re: 1gbps between 2 Windows Servers

    RSS and TCP/IP offloading came with SP2 for Windows 2003.
    I don’t know if you use SP2. If yes please review:
    http://support.microsoft.com/kb/948496

    Avatar
    ikon
    Member
    #354205

    Re: 1gbps between 2 Windows Servers

    Ok i have tried both but no joy.

    here is screen shot after a rebooted.

    Still get 140Mbps.. Frustrating, i will recheck the cable connected between the 2 machines.

    screenshot.jpg

    Avatar
    joeqwerty
    Moderator
    #301402

    Re: 1gbps between 2 Windows Servers

    Where did you come up with your expectation of 400Mbps? Did you just pick that randomly or did you do some calculations and that’s what you came up with? You can roughly estimate throughput using the formula: TCP Window Size divided by Round Trip Time. You also need to consider that many small files will take longer to copy than one large file. You also need to consider the xcopy options you are using as the Z and V options are going to add overhead and slow down the copy process. Try it without those options and see how fast it is.

    Avatar
    ikon
    Member
    #354206

    Re: 1gbps between 2 Windows Servers

    I did not do any calculations i just assumed someting in between, but im was pretty sure it was going to be more than 140Mbps.

    The tcp windows size is dynamic in windows server 2003, all-though i can set it.

    Using the correct formula for 100Mbit connection

    100 Mbits/s and the round trip time was 5 msec, the TCP window should be 100×10^6 times 5×10^-3 (65 kilobytes).

    Im using 1000Mbits and round trip is 1 msec
    1000×10^6 times 1×10^-3 (1000 Kilobytes)

    Throughput calc

    RCV buffer size / RTT = Max TCP throughput = ? bps, (Buffer size is normally 64Kbps)
    ex) (64Kbyte x 8bit) / 0.17 = 3011764 bps = 3Mbps, (RTT=170ms)

    In my case 1000Kb / .001 = 1000000000 bps = 1000Mbps

    8)

    So your saying i must manually set my tcp window size to this.

    I will try this reluctantly, as windows is supposed to calcumate this all for me.

    EDIT..

    I will try without the option in xcopy, the files i am copying are all large >1GB one file is actually 65GB ins size.

    i have recently just tried a drag n drop copy of some 1GB files on another server to the same Ethernet disk, this time at 220Mbps, so i am thinking without those xcopy options it will provide better throughput, i would just like to know what expect through-put wise copying data using 1Gbps Ethernet cards.

    Avatar
    L4ndy
    Member
    #275441

    Re: 1gbps between 2 Windows Servers

    How about using Server Performance Advisor to have more of an idea where exactly the bottleneck is if you haven’t already done so? It could well be a Disk I/O issue or s’thing else. You’ll get a very detailed insight with SPA.

    Ta

    Avatar
    ikon
    Member
    #354207

    Re: 1gbps between 2 Windows Servers

    Thanks i will give that a try now.

    Avatar
    ikon
    Member
    #354208

    Re: 1gbps between 2 Windows Servers

    Avg Disk Queue Lenght of 10, baring in mind that there are 16 SAS 15k rpm drives.

    Avatar
    ikon
    Member
    #354209

    Re: 1gbps between 2 Windows Servers

    OK i removed the Z and V options from Xcopy and can now get 220Mbps, which is same as another machine i have tried with 0 load.

    So without further tweaking of things like “Tcp window size” i will assume this is normal for now.

    Thanks for all of your help.

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