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QFX USB Speed

‎07-02-2019 05:49 PM

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.

3 REPLIES 3
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Re: QFX USB Speed

‎07-02-2019 06:25 PM

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/specification...

 

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.

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Re: QFX USB Speed

[ Edited ]
‎07-02-2019 09:03 PM

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.

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Solution
Accepted by topic author smicker
‎07-03-2019 03:01 PM

Re: QFX USB Speed

‎07-03-2019 03:01 PM

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