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  • Erratic Network Speed behavior in Windows 2003 Ent

    I'm running Windows Server 2003 Enterprise Edition on 2 servers.

    Server 1: Runs SQL Server, Active Directory
    Server 2: Runs Terminal Server, Application Server

    I have a SQL database backup file of about 22 GB's that gets written daily to Server 1: c:\backup. When I'm on Server 1 and copy and paste the backup file to a mapped drive on Server2, I find my network speed is slow, then decently fast, then slow, then fast... And it takes the file much longer to copy than it should really take. I'm attaching screenshots of Taskman showing the speed jumps and slowdowns.

    The first screenshot shows the erratic behavior. i.e. Fast speeds, and fairly slow speeds. The second screenshot shows how the network speed goes to zero after the file has completed copying.

    Any ideas on what might be causing this? I've looked at network card settings, network drivers, physical cabling, physical hardware/switches, etc. I actually have identical servers, with different hardware (network switches) and cables, installed at another location and I see the exact same behavior there, as well. All servers in all locations are running the same hardware (Windows Server 2003). They are SuperMicro servers, pretty beefy, with 4GB's RAM, 8 cores each (Quad Xeon's, E5420's), etc.

    Thanks in advance for any help you can provide.
    Attached Files

  • #2
    Re: Erratic Network Speed behavior in Windows 2003 Ent

    done any performance monitoring ?

    things like disk read and write rates on both servers?
    things like network queue lengths, disk queue lengths, packets received/dropped etc?
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    • #3
      Re: Erratic Network Speed behavior in Windows 2003 Ent

      Originally posted by tehcamel View Post
      done any performance monitoring ?

      things like disk read and write rates on both servers?
      things like network queue lengths, disk queue lengths, packets received/dropped etc?
      Thank you for the response. I have tried setting that up (in the past - this is something I've seen for over a year) but I wasn't able to (apparently) understand what I was looking at. My background is setting up servers, hardware, software, Java development, etc. And I've never seen this kind of thing to try to troubleshoot. (i.e. The speed is perfectly fine at one point, then just comes to a crawl for a bit) Is this easy to setup and configure and understand? Perhaps I'm doing it wrong.

      Any insight is greatly appreciated!

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      • #4
        Re: Erratic Network Speed behavior in Windows 2003 Ent

        Have a play around in Perfmon, referring to Google for some pointers and you'll pick it up quickly enough. tc has already suggested some good counters to look at.
        Gareth Howells

        BSc (Hons), MBCS, MCP, MCDST, ICCE

        Any advice is given in good faith and without warranty.

        Please give reputation points if somebody has helped you.

        "For by now I could have stretched out my hand and struck you and your people with a plague that would have wiped you off the Earth." (Exodus 9:15) - I could kill you with my thumb.

        "Everything that lives and moves will be food for you." (Genesis 9:3) - For every animal you don't eat, I'm going to eat three.

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        • #5
          Re: Erratic Network Speed behavior in Windows 2003 Ent

          Originally posted by gforceindustries View Post
          Have a play around in Perfmon, referring to Google for some pointers and you'll pick it up quickly enough. tc has already suggested some good counters to look at.
          Makes sense. I will be able to test this again in the next week or so...

          Comment


          • #6
            Re: Erratic Network Speed behavior in Windows 2003 Ent

            Here is a screen shot of the performance monitor on the 'receiving' server. This is at a time when the speed has slowed down to 2.5% of LAN adapater capacity.
            Attached Files

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            • #7
              Re: Erratic Network Speed behavior in Windows 2003 Ent

              Screenshot of receiving server when the speed picks back up.
              Attached Files

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              • #8
                Re: Erratic Network Speed behavior in Windows 2003 Ent

                Screenshot of sending server when speeds are slow.
                Attached Files

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                • #9
                  Re: Erratic Network Speed behavior in Windows 2003 Ent

                  Screenshot of sending server when speeds were fast, slowed down, and then completed the file transfer.
                  Attached Files

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                  • #10
                    Re: Erratic Network Speed behavior in Windows 2003 Ent

                    Screenshot from receiving server when files were slow and then file transfer completed.
                    Attached Files

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                    • #11
                      Re: Erratic Network Speed behavior in Windows 2003 Ent

                      If anyone has any feedback on deciphering these, I'd appreciate it. I don't see anything that is obviously wrong here.

                      Comment


                      • #12
                        Re: Erratic Network Speed behavior in Windows 2003 Ent

                        Ok, lets see if we can work out where the speed loss is, rather then trying to guess by looking at lines :P

                        If you are able to disconnect your servers from the network for 10 mins, try this.

                        A) Replace both server with a computer, and try the file transfer. This will see if you have a problem with your network hardware (switchs, cables, ect). I have seen major drops in speed from network cables being run next to power leads. The power makes a small EM field, and that is sometimes enough to get past the UTP shielding.

                        If once you have done this, the file is transfered at a constant rate, try this

                        B) Reconnect the SQL server, and try to transfer the backup file to the Laptop replacing the TS. Monitor the speed.

                        C) Repeat process, but with the other server/laptop.

                        D) Also, having AD and SQL on the same server, does that not mean the server will be coping a heap of constant requests? It could be that the server coping the data is just doing alot of other network stuff.

                        Wofen
                        Good to be back....

                        Comment


                        • #13
                          Re: Erratic Network Speed behavior in Windows 2003 Ent

                          Originally posted by Wofen View Post
                          D) Also, having AD and SQL on the same server, does that not mean the server will be coping a heap of constant requests? It could be that the server coping the data is just doing alot of other network stuff.

                          Wofen
                          No, this is probably not the case. I only work on the system when there is NOTHING going on. No users have access (I shut down VPN/remote), make sure no one is doing anything. The server has no tasks running, etc...

                          This behavior is consistent between two completely different networks, but, as my original post points out, similar hardware. So both networks have a SQL/AD server and a TS/App/IIS server.

                          Copying from Server1 to Server2 over a share is where this is having issues. I'm finding it hard to believe that no one has really seen this before. Given that fact that I have unrelated systems in separate locations and they both have this problem. I thought it was network drivers or some other kind of software issue, but I have everything up to date the moment.

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                          • #14
                            Re: Erratic Network Speed behavior in Windows 2003 Ent

                            Originally posted by Wofen View Post
                            The power makes a small EM field, and that is sometimes enough to get past the UTP shielding.
                            OT and perhaps a little overly pendantic, but UTP isn't shielded. Hence the U.
                            Gareth Howells

                            BSc (Hons), MBCS, MCP, MCDST, ICCE

                            Any advice is given in good faith and without warranty.

                            Please give reputation points if somebody has helped you.

                            "For by now I could have stretched out my hand and struck you and your people with a plague that would have wiped you off the Earth." (Exodus 9:15) - I could kill you with my thumb.

                            "Everything that lives and moves will be food for you." (Genesis 9:3) - For every animal you don't eat, I'm going to eat three.

                            Comment


                            • #15
                              Re: Erratic Network Speed behavior in Windows 2003 Ent

                              This screen shot shows moving the file from a Mac OS X Snow Leopard box over to the same (Server2) server of the same file. Probably about 35MB/s transfer speed. 14GB file takes about 6 -7 minutes to copy.

                              Between the two servers, the same file takes 25 minutes to copy. Given the lag slow downs and the temporary fast performances.

                              Amazing that a Mac to Windows is better than Windows 2003 <-> Windows 2003
                              Attached Files

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