file copy in shared folder : 500kB/s max speed. Why isn't it more?

    • OMV 4.x
    • file copy in shared folder : 500kB/s max speed. Why isn't it more?

      hello

      I launched the file copy, the file being in a shared directory of the OMV nas. The copy is initiated from a linux os, linked to the NAS by a CPL (a box that is plugged in the electricity). The nas itself is linked to the internet box via an ethernet wire.

      the max copy rate is about 500 kB/s. I wonder why is is not more.

      hard disk <------> nas <------> internet box <------> computer
      ..............USB 2.0.....ethernet...............electricity

      the slower element should be USB 2 but it is still 50MB/S...

      thank you

      The post was edited 1 time, last by lowley ().

    • lowley wrote:

      the slower element should be USB 2 but it is still 50MB/S
      No way. Slightly exceeding 40 MB/s is the maximum possible with USB2.

      I've to admit that I've not the slightest idea which equipment you use (I understood 'CPL' is a PowerLine adapter but where comes USB2 into play?) but as soon as you use a topology using a 'shared medium' prone to interferences (Wi-Fi, PowerLine) you should forget about every theoretical bandwidth calculation since real world throughput is always magnitudes lower.

      I would install iperf3 on both machines and check with this. If reported throughput is low you know you've a network problem (sending frames and packets through modern networks is not like 'water in pipes' since transmissions are prone to collissions/errors and mechanisms to detect/recover from this exist which can result in your network being flooded with +90% retransmitted packets)
    • hello

      IPerf3 tells me the bandwidth is 10MB/S, between the nas and the linux computer. it's 20 times faster than what I had!
      in fact, I get the same speed as if I would want to access to the outside of my lan.
      but in this test there is no use of the USB 2 connection to the hard disk (an SSD).
    • lowley wrote:

      but in this test there is no use of the USB 2 connection to the hard disk (an SSD)
      Now I get it, the disk is USB 2.0 attached to the NAS. So time to test this individually, maybe there's the bottleneck.

      I wrote some time ago how to diagnose 'NAS performance problems' with Single Board Computers but of course this also applies to 'real computers' or even servers: linux-sunxi.org/Sunxi_devices_…F_Identifying_bottlenecks
    • raulfg3 wrote:

      please read problem nº 5: Solutions to common problems
      A bit unlikely to get only 5% network throughput caused by unoptimized Samba settings. :)

      And unfortunately the thread starter did not even mention which protocol he uses and so on... if it's Linux to OMV over SMB then there's also the possibility that the (or better say another) bottleneck is on the client if Gnome's gvfs is used...