network speeds over time..

Discussion in 'Server Networking' started by Justin Rich, Nov 15, 2007.

  1. Justin Rich

    Justin Rich Guest

    I was wondering if anyone could shed some light on a network speed issue. we
    have a database to backup that's 766GB. at first the backup starts off
    pretty well at 30MB/s but over time it just keeps getting slower and
    slower... towards the end it ended up under 10MB/s

    I have tried different methods of copying the file and it doesn't seem to
    matter the performance degrades over time regardless.

    its obviously hard to give info on this, but I was wondering if this was a
    known issue and if there was any way around it. typically restarting the
    copy helps with the speed, but that really isn't the best option.

    what would cause the speed to drop?

    Thanks
    Justin
     
    Justin Rich, Nov 15, 2007
    #1
    1. Advertisements

  2. Which methods you tried ?
    Robocopy ?
    eseutil ?
     
    Mathieu CHATEAU, Nov 15, 2007
    #2
    1. Advertisements

  3. Justin Rich

    Justin Rich Guest

    I tried a straight copy (pretty slow) I tried robocopy (was ok, but wasn't
    the highest speeds) and I used Repliweb and netbackup, both of which started
    off at about 30MB/s which only held for roughly 2 hours and after that I saw
    a steady continuous drop in speed.


    Justin
     
    Justin Rich, Nov 15, 2007
    #3
  4. Can you try with eseutil ? it is meant to copy very large file
     
    Mathieu CHATEAU, Nov 16, 2007
    #4
  5. Justin Rich

    Justin Rich Guest

    Thats a good idea, i actually forgot about that.. from my understanding most
    programs use a windows copy function where as the eseutil actually uses a
    read/write method which makes it quicker with less overhead.

    i'll give that a try but mostly i'd like to figure out why a large(long)
    transfer like this would start to slow down over time.

    Justin
     
    Justin Rich, Nov 16, 2007
    #5
  6. If it doesn't do the job:
    Check for antivirus (to exclude source & destination on both side)
    check for scheduled task that may makes a lot of I/O (defrag, full antivirus
    scan)
    You may use a sniffer like Wireshark or Microsoft Network Monitor 3.1 to
    check against packets. As Laura Chappell said during techED, "Packets never
    lie !"
     
    Mathieu CHATEAU, Nov 16, 2007
    #6
  7. Justin Rich

    Justin Rich Guest

    awesome, looking in to that now. we have 2.6 but we can probably get it
    upgraded.

    thanks for the info

    Justin
     
    Justin Rich, Nov 19, 2007
    #7
  8. Justin Rich

    Justin Rich Guest

    there are no scheduled tasks, its just a steady drop. the link rakefet sent
    in regards to repliweb gives a pretty good pictorial of whats going on with
    their example of the FTP transfer which i guess they are saying is packet
    loss and TCP errors.

    i have used wireshark but im still kind of new too it. is there any links
    for web resources on this topic in particular or could you give me a brief
    run down of what i would be looking at/for?

    Thanks
    Justin
     
    Justin Rich, Nov 19, 2007
    #8
  9. Justin Rich

    Justin Rich Guest

    ps: im using eseutil right now and its off to a strong start using 50% of a
    gig connection. I have started some perfmon logs to keep an eye on this to
    see how it degrades over time.

    Justin
     
    Justin Rich, Nov 19, 2007
    #9
  10. Looks great, keep us informed !
     
    Mathieu CHATEAU, Nov 19, 2007
    #10
  11. Justin Rich

    Justin Rich Guest

    with eseutil it took about 4 and a half hours to transfer 830GB... worked
    out pretty well and held strong the whole time.
    Going to try the RDS since we own it and see how that works out, but im
    pretty happy with how eseutil handled it.

    Thanks for the help.

    Justin
     
    Justin Rich, Nov 19, 2007
    #11
  12. great :)
     
    Mathieu CHATEAU, Nov 19, 2007
    #12
    1. Advertisements

Ask a Question

Want to reply to this thread or ask your own question?

You'll need to choose a username for the site, which only take a couple of moments (here). After that, you can post your question and our members will help you out.