This article describes how to perform Format Install by using the "install --format" command on legacy Juniper Networks EX Series Switches platforms and how to resolve any common problems that you may encounter while performing this procedure.

Caution: "Format Install" should be the last recovery method to use to restore a switch because this process will erase all files, including the configuration files, by formatting the file system. Therefore, before performing a Format Install, you must ensure that best backup procedures are in place for recovery from any possible file loss.

This method also applies for the EX4300. 

(Note: This article replaces deprecated article ID: KB10386 [juniper.net])

NOTE: Contact Juniper Support if you need a Root Cause Analysis prior to system recovery because all files will be deleted after the process is complete.

Prior to using either method, isolate the affected device if it is part of a Virtual Chassis or Virtual Chassis Fabric.

​Method 1 Using a USB Device

1. To perform this recovery installation, the USB device should be formatted to FAT-32 and should be empty (recommended USB size: 1GB, 2GB, or 4GB). Review the complete USB compatibility specifications listed in USB Port Specifications for an EX Series Switch .

2. Copy the Junos OS package to the USB device.

3. Power off the EX switch.

4. Plug the USB device into the EX switch.

5. Power on the EX switch.

6. When you see the " Hit [Enter] to boot immediately, or space bar for command prompt " message prompt appear, press the Space bar to get the loader prompt.
   (To avoid missing it, you may start pressing the Space bar some seconds before the message prompt appears).

7. Issue the install command with the format option:

loader> install --format file:///<Junos package name>

For example:

loader> install --format file:///jinstall-ex-4200-15.1R7-S6.3-domestic-signed.tgz

Note: If you encounter any issues during this procedure, refer to Possible Problems During the Format Process and Their Fixes .

​Method 2 Using TFTP

Prepare a TFTP server and put the corresponding image in the TFTP root directory.

For example, the IP address of the TFTP server is 192.168.100.1/24 and the filename of the image is jinstall-ex-10.0R2-domestic-signed.tgz .

Directly connect the EX Series device's management port to the TFTP server, or make sure that they are in the same broadcast domain.

1. Connect a terminal to the EX switch console port and power on the switch.

2. When you see the " Hit [Enter] to boot immediately, or space bar for command prompt " message prompt appear, press the Space bar to get the loader prompt.
   (To avoid missing it, you may start pressing the Space bar some seconds before the message prompt appears).

3. Press the Space bar to enter the manual loader. The  loader>  prompt displays.

4. Substitute the following parameters with the corresponding IP addresses of your network: ( Note: In case the TFTP server is not in the same IP segment, the gateway IP address will also be needed.)

loader> set ipaddr=192.168.100.2
loader> set netmask=255.255.255.0
loader> set gatewayip=192.168.100.254
loader> set serverip=192.168.100.1
loader> install --format tftp://<tftp server>/<Junos package name>

For example:

loader> install --format tftp://192.168.100.1/jinstall-ex-4200-15.1R7-S6.3-domestic-signed.tgz

5. Issue the install command with the format  option to install the Junos OS image via TFTP.

Note: If you encounter any issues during this procedure, refer to Possible Problems During the Format Process and Their Fixes .

The part of the boot log shown below is related to the steps listed above:

Consoles: U-Boot console  
Found compatible API, ver. 7

FreeBSD/PowerPC U-Boot bootstrap loader, Revision 2.1
([email protected], Wed Feb  6 11:23:55 PST 2008)
Memory: 1024MB
Loading /boot/defaults/loader.conf 
/kernel data=0x9dc348+0x6df44 syms=[0x4+0x87bb0+0x4+0x8e152]

Hit [Enter] to boot immediately, or space bar for command prompt.< Press the Space bar.

Type '?' for a list of commands, 'help' for more detailed help.
loader>        
loader> set ipaddr=192.168.100.2
loader> set netmask=255.255.255.0
loader> set serverip=192.168.100.1
loader> install tftp://192.168.100.1/jinstall-ex-10.0R2-domestic-signed.tgz
Speed: 100, full duplex
Package /jinstall-ex/mx-10.0R2-domestic-signed.tgz is signed...
/kernel data=0x504104+0x32e60 syms=[0x4+0x50a00+0x4+0x6366f]
Kernel entry at 0xa0000100 ...
GDB: no debug ports present
KDB: debugger backends: ddb
KDB: current backend: ddb
Copyright (c) 1996-2008, Juniper Networks, Inc.
All rights reserved.
Copyright (c) 1992-2006 The FreeBSD Project.

Possible Problems During the Format Process and Their Fixes

• Issue 1: Device stuck after the following lines are output:

FreeBSD/PowerPC U-Boot bootstrap loader, Revision 2.2
([email protected], Wed May 19 06:04:27 UTC 2010)
Memory: 1024MB
Loading /boot/defaults/loader.conf 

FIX: Reboot the switch again and press  Ctrl + C . (If you get the " => " prompt, refer to Issue 3 ) .

USB:   scanning bus for devices... 2 USB Device(s) found <-- Type Control + C here.      

• Issue 2: Getting the following errors during the boot sequence instead of a loader prompt:

Request Sense returned 00 00 00
Device NOT ready  

FIX: Reboot the switch and press Ctrl + C to get to Uboot mode (then refer to Issue 3 ):

USB:   scanning bus for devices... 2 USB Device(s) found  <-- Type Control + C here.
       scanning bus for storage devices... 1 Storage Device(s) found

• Issue 3: Getting Uboot mode  instead of the loader  prompt (or you are here after performing the previous steps):

=>
=>

FIX: Run the following commands, which will reboot the switch, and break the sequence to get the loader prompt:

=> setenv loaddev disk66  (Use disk numbers other than 0 and 1, which are intentionally invalid disk numbers, for example: disk99, or disk12.)
=> saveenv
=> reset

• Issue 4: Getting the DB mode  prompt instead of the loader prompt:

db>

FIX: Run the following command and break the sequence to get the loader prompt (power-cycle again if needed):

db> cont

• Issue 5: Getting the following errors:

cannot open package (error 60)
cannot open package (error 60)
cannot open package (error 22)

FIX: Try a new Juniper Supported USB Device . If the issue persists, refer to [EX] Error "cannot open package" seen when performing "format install" from loader for troubleshooting further.

Refer to Troubleshooting Software Installation on EX Series Switches for additional information.

You can also try a different software version. If the issue persists, open a case with JTAC.

• [Upgrade EX Switch] Stage 2 - Backup configuration

• Introduction to the Junos Operating System