Switching

Expand all | Collapse all

QFX USB Speed

Jump to Best Answer
  • 1.  QFX USB Speed

     
    Posted 07-02-2019 17:50

    Does anyone know if the QFX-5100 USB port supports 3.0 speeds? The question comes from a desire to boot from image recovery media as quickly as possible.



  • 2.  RE: QFX USB Speed

     
    Posted 07-02-2019 18:25

    Hi smicker,

     

    Yes the USB 3.0 should work as QFX5100 supports 2.0 and later:

    https://www.juniper.net/documentation/en_US/release-independent/junos/topics/reference/specifications/port-qfx3500-usb.html

     

    Have the USB FAT-32 formatted, that should work.

     

    Also, if trying recovery, then from the “Select a recovery image”/GNU, if we select the GRUB and follow the Junos recovery procedure with format Junos data disk and format Junos config disk, that should work.

     

    Hope this helps.

    Regards,
    -r.

    --------------------------------------------------

    If this solves your problem, please mark this post as "Accepted Solution."
    Kudos are always appreciated :).



  • 3.  RE: QFX USB Speed

     
    Posted 07-02-2019 21:04

    My question is if it supports 3.0 speeds. Supporting 2.0 devices or later is true of all USB 2.0 ports as well.



  • 4.  RE: QFX USB Speed
    Best Answer

     
    Posted 07-03-2019 15:01

    To answer my own question, and in case this information is useful to anyone else:

     

    The USB ports appear to be 2.0:

     

    usb1: EHCI version 1.0
    usb1: <EHCI (generic) USB 2.0 controller> on ehci0
    usb1: USB revision 2.0

     

    Data transfer speeds to a 3.0 device overall showed higher throughput than to a 2.0 device, but not dramatically so. Regardless, total time to restore from a USB install image was identical whether using 2.0 or 3.0: 7 minutes 40 seconds.

     

      USB2.0 USB3.0
    fs copy from 125.9Mb/s 139.9Mb/s
    fs copy from (to /dev/null) 128.5Mb/s 170.2Mb/s
    fs copy to 32.8Mb/s 52.5Mb/s
    dd copy to 35.0Mb/s 112.4Mb/s
    boot & install from USB 13.7Mb/s 13.7Mb/s