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Slow Network Performance

    Question

  • I have recently purchased 4 Dell R720's and I'm noticing a big network performance issue.  These systems are running Windows Server 2012 Standard 16gb of RAM and 6x 1.2tb disks in a Raid 5. These systems are connected to a gigabit cisco switch.  The issue i'm seeing is when I try to transfer files to these new servers im only able to achieve about 200mbps of throughput.  The servers are under minimal load and should be able to max out (or get close) the gig connection between servers.  I have already updated all drivers and tried disabled QoS on the nic.  Any help is appreciated here! Thanks!
    Saturday, January 25, 2014 6:48 PM

Answers

  • I have recently purchased 4 Dell R720's and I'm noticing a big network performance issue.  These systems are running Windows Server 2012 Standard 16gb of RAM and 6x 1.2tb disks in a Raid 5. These systems are connected to a gigabit cisco switch.  The issue i'm seeing is when I try to transfer files to these new servers im only able to achieve about 200mbps of throughput.  The servers are under minimal load and should be able to max out (or get close) the gig connection between servers.  I have already updated all drivers and tried disabled QoS on the nic.  Any help is appreciated here! Thanks!
    Use NTtcp and IPerf to isolate the issue. Start with turning OFF all the teaming and QoS, remove switches (use direct cable connection), update NIC drivers to the most recent ones. You should have wire speed with TCP (~900-950 Mbps) before moving forward with SMB related tests.

    StarWind VSAN [Virtual SAN] clusters Hyper-V without SAS, Fibre Channel, SMB 3.0 or iSCSI, uses Ethernet to mirror internally mounted SATA disks between hosts.

    Monday, January 27, 2014 11:37 AM

All replies

  • 1. RAID 5 in known for poor write in performance. RAID 1 is preferred (Alternatively RAID 10).

    2. Teaming enables greater speed. Hope you use Dell's drivers

    3. Use performance monitor to analyze your system (Avoid queue lenght >=2)

    4. Play with NIC parameters

    5. Try combinations on NIC and switch (auto/fixed speed, fixed speed/fixed speed). Cisco may have troubleshooting procedures.

    6. Check Event log (for sure that there is no problem that cause the lower speed)

    Regards

    Milos

    Saturday, January 25, 2014 7:35 PM
  • I have recently purchased 4 Dell R720's and I'm noticing a big network performance issue.  These systems are running Windows Server 2012 Standard 16gb of RAM and 6x 1.2tb disks in a Raid 5. These systems are connected to a gigabit cisco switch.  The issue i'm seeing is when I try to transfer files to these new servers im only able to achieve about 200mbps of throughput.  The servers are under minimal load and should be able to max out (or get close) the gig connection between servers.  I have already updated all drivers and tried disabled QoS on the nic.  Any help is appreciated here! Thanks!
    Use NTtcp and IPerf to isolate the issue. Start with turning OFF all the teaming and QoS, remove switches (use direct cable connection), update NIC drivers to the most recent ones. You should have wire speed with TCP (~900-950 Mbps) before moving forward with SMB related tests.

    StarWind VSAN [Virtual SAN] clusters Hyper-V without SAS, Fibre Channel, SMB 3.0 or iSCSI, uses Ethernet to mirror internally mounted SATA disks between hosts.

    Monday, January 27, 2014 11:37 AM