Description

This article explains how to mount a USB drive on an MX150 device and copy files to or from the device via the USB drive.

Solution

The following procedure allow users to mount a USB device on MX150.  This can be helpful if network connectivity is unavailable and you need to copy files to or from the device.
Note: the USB drive is detected on Linux host side /dev directory, not on FreeBSD (Junos VM) /dev directory.

  1. Change the shell from Junos CLI to BSD shell. 

    user@mx150> start shell
%
  2. Before inserting the USB device, check current disk device partitions. "192.168.1.1" is a fixed address for Linux host via internal connection.
    You can issue Linux command via SSH connection with Juniper private routing instance onward. 
    % ssh -JU __juniper_private4__ [email protected] 'ls /dev/sd*'
/dev/sda
/dev/sda1
/dev/sda2
/dev/sda3
/dev/sda4
/dev/sda5
/dev/sda6
/dev/sda7  <-- Currently there is only "sda(and number at the tail)" device found

  3. Insert USB stick to MX150 box USB port. You can check the disk partition of USB from dmesg. 

    % ssh -JU __juniper_private4__ [email protected] 'dmesg | grep -i scsi'
[600876.608516] scsi7 : usb-storage 3-1:1.0
[600877.608645] scsi 7:0:0:0: Direct-Access     SanDisk  Cruzer Blade     1.27 PQ: 0 ANSI: 6
[600877.616627] sd 7:0:0:0: [sdb] Attached SCSI removable disk <-- [sdb] is the device name

    Note: Or, you can check the disk partition of USB by lsblk command as well. 

    % ssh -JU __juniper_private4__ [email protected] 'lsblk -S'
NAME HCTL       TYPE VENDOR   MODEL             REV TRAN
sda  0:0:0:0    disk ATA      StorFly VSFBM6CC 0629 sata
sdb  7:0:0:0    disk SanDisk  Cruzer Blade     1.27 usb    <-- sdb shows usb transport type

    There is certainly such disk partition attached in Linux host. 

    %  ssh -JU __juniper_private4__ [email protected] 'ls /dev/sd*'
/dev/sda
/dev/sda1
/dev/sda2
/dev/sda3
/dev/sda4
/dev/sda5
/dev/sda6
/dev/sda7
/dev/sdb    <-- "sdb" device is attached. (The last letter "b" may vary depending on your circumstance.)
/dev/sdb1

  4. Create a directory for the USB drive to mount in Linux host side. 

    % ssh -JU __juniper_private4__ [email protected] 'mkdir /var/tmp/usb'
%

  5. Mount the USB drive to the /var/tmp/usb directory in Linux host side. 

    % ssh -JU __juniper_private4__ [email protected] 'mount /dev/sdb /var/tmp/usb'

    Check if it is properly mounted in Linux host. 

    % ssh -JU __juniper_private4__ [email protected] 'mount | grep usb'
/dev/sdb on /var/tmp/usb type ext2 (rw,relatime,errors=continue,user_xattr,acl)  <-- You can see this line

  6. Copy any of files:

    a.  From MX150 storage to the USB disk(/var/tmp/usb directory) with the following SCP command:

    scp -JU __juniper_private4__ <filename> [email protected]:/var/tmp/usb/ 
    % scp -JU __juniper_private4__ /var/tmp/testfile.txt [email protected]:/var/tmp/usb/  <-- source-file name is "testfile.txt" in current directory
testfile.txt                                  100%    9     0.0KB/s   00:00  <-- transfer completed

%ssh -JU __juniper_private4__ [email protected] 'ls /var/tmp/usb'
testfile.txt  <-- you can see the same file in the USB mounted directory

    b.  From the USB disk to MX150 storage with the following SCP command:

    scp -JU __juniper_private4__ [email protected]:/var/tmp/usb/ <filename> <target_directory_in_MX150_Junos> 
    % scp -JU __juniper_private4__ [email protected]:/var/tmp/usb/testfile.txt /var/tmp/  <-- source-file name is "testfile.txt" in USB destins "/var/tmp" directory in MX150

  7. Unmount the USB drive after the file is completely copied: 

    % ssh -JU __juniper_private4__ [email protected] umount /var/tmp/usb

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