How to mount USB flash drive on Juniper EX series switches

Summary:

Am trying to upgrade my juniper EX4200 from JUNOS Base OS Software Suite [12.3R9.4] to 12.3R12.4 in preparation for virtual chassis, Juniper recommends that all switches within the same virtual chassis run the same software version. And because my VC will be a mixture of EX4550/EX4500/EX4200, juniper recommended that i use 12.3R12.4

So i have my software already downloaded and on a flash disk

Problem or Goal:

I need to transfer the software to the switches using a flash drive

Cause:

You probably have no network connectivity to the switches to do an FTP transfer, or you are working on a new switch.

Solution: 

1. Enter the shell as root:

root> start shell user root
root@:RE:0%

2. Before inserting the USB device, perform the following:

root@:RE:0% ls /dev/da*
/dev/da0        /dev/da0s1c     /dev/da0s2c     /dev/da0s3d     /dev/da0s4c
/dev/da0s1      /dev/da0s2      /dev/da0s3      /dev/da0s3e     /dev/da0s4d
/dev/da0s1a     /dev/da0s2a     /dev/da0s3c     /dev/da0s4

3. Insert the USB drive in the USB port. The following output will be displayed:

root@:RE:0% umass1: Generic Mass Storage, rev 2.00/1.06, addr 3
da1 at umass-sim1 bus 1 target 0 lun 0
da1: <Generic Flash Disk 8.07> Removable Direct Access SCSI-4 device
da1: 40.000MB/s transfers
da1: 7800MB (15974400 512 byte sectors: 255H 63S/T 994C)

root@:RE:0% ls /dev/da*
/dev/da0        /dev/da0s2      /dev/da0s3c     /dev/da0s4c
/dev/da0s1      /dev/da0s2a     /dev/da0s3d     /dev/da0s4d
/dev/da0s1a     /dev/da0s2c     /dev/da0s3e     /dev/da1
/dev/da0s1c     /dev/da0s3      /dev/da0s4      /dev/da1s1

Note: if you compare the "ls /dev/da*" output before inserting the flash drive and after inserting the drive, you will notice these have been added:

/dev/da1 and "/dev/da1s1"

Your USB drive is located here "/dev/da1s1"

4. Create a directory for the USB drive to mount to:

root@:RE:0% mkdir /var/tmp/usb

5. Mount the USB drive to the /var/tmp/usb directory:

root@:RE:0% mount_msdosfs /dev/da1s1 /var/tmp/usb

root@:RE:0% ls /var/tmp/usb
jinstall-ex-4200-12.3R12.4-domestic-signed.tgz
jinstall-ex-4500-12.3R12.4-domestic-signed.tgz

Problem Solved?

Yes 

6. You can now copy any of the USB files to the /var/tmp directory on the switch:

root@:RE:0% cp /var/tmp/usb/jinstall-ex-4200-12.3R12.4-domestic-signed.tgz /var/tmp

7. Now unmount the USB drive after the file is completely copied:

root@:RE:0% umount /var/tmp/usb

References: juniper.net