Description

This article explains how to make an install-media USB disk from MX150 platform.

Solution

The following procedure allows users to create an install media on MX150 devices.

Note: The USB drive is detected on Linux host side /dev directory, not on FreeBSD(Junos VM) /dev directory. The example below uses "install-media-host-usb-mx100-x86-64-17.4R1.16-secure.img" as the install media image file name.

  1. Store the MX150 install media image file to MX150 box (in Junos CLI). 
    user@mx150> start shell

% scp <your_server_username>@<your_server_address>:install-media-host-usb-mx100-x86-64-17.4R1.16-secure.img /var/tmp/
[email protected]'s password:

% ls -l /var/tmp/
-rw-r--r--  1 root     20  1887436800 Dec 21 22:11 install-media-host-usb-mx100-x86-64-17.4R1.16-secure.img
  2. Move to Linux host prompt. "192.168.1.1" is a fixed address for Linux host via internal connection. 
    % ssh -JU __juniper_private4__ [email protected]
Last login: Tue Apr 17 09:52:43 2018 from mx150

root@mx150-node:~#   <-- "-node" indicates you're in Linux host shell

    Note: Unless you're logging in as root user on Junos, you need to specify username as "root@" in ssh command.
     

  3. Insert USB stick to MX150 box USB port. You can check the disk partition of USB from dmesg. 
    root@mx150-node:~# 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. 
    root@mx150-node:~# 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
  4. Copy the install media image file from Junos VM to Linux host. "192.168.1.2" is fixed address for Junos VM via internal connection. 
    root@mx150-node:~# scp <username>@192.168.1.2:/var/tmp/install-media-host-usb-mx100-x86-64-17.4R1.16-secure.img /var/tmp/
Password:

root@mx150-node:~# ls -l /var/tmp/
-rw-r--r-- 1 root root 1887436800 Apr 18 18:49 install-media-host-usb-mx100-x86-64-17.4R1.16-secure.img

    Note: The install media image is huge, so it is better to put the file in /var/tmp directory.
     

  5. Copy the image block by block with the following dd command.

        dd if=/dev/zero of=/dev/ <disk_partition> bs=1M count=20
        dd if= <file_name> of=/dev/ <disk_partition> bs=1M 
    root@mx150-node:~# dd if=/dev/zero of=/dev/sdb bs=1M count=20
20+0 records in
20+0 records out
20971520 bytes (21 MB) copied, 0.015077 s, 1.4 GB/s

root@mx150-node:~# dd if=/var/tmp/install-media-host-usb-mx100-x86-64-17.4R1.16-secure.img of=/dev/sdb bs=1M
1800+0 records in
1800+0 records out
1887436800 bytes (1.9 GB) copied, 1.13771 s, 1.7 GB/s

  6. Eject the install USB media.

    [Option] When you boot with install media in MX150 in order to recover, you need to run the reboot command in Linux host side . Or power cycle for the MX150 box. If you reboot only in Junos, it does not start USB boot menu. 
    root@mx150-node:~# reboot
INIT: Sending processes the TERM signal
<..snip..>

Modification History

2020-10-26: Article reviewed for accuracy, no changes required; article accurate and valid

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