Juniper QFX5100, Hardware Manual

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Performing a Recovery Installation on a QFX5100 Switch
If Junos OS on your switch is damaged in some way that prevents the software from
loading correctly, you may need to perform a recovery installation using an emergency
boot device (for example, a USB flash drive) to restore the default factory installation.
Once you have recovered the software, you need to restore the device configuration. You
can either create a new configuration as you did when the device was shipped from the
factory, or if you saved the previous configuration, you can simply restore that file to the
switch.
If at all possible, you should try to perform the following steps before you perform the
recovery installation:
1.
Ensure that you have an emergency boot device to use during the installation. See
“Creating an Emergency Boot Device for a QFX Series Device” on page 225 for
information on how to create an emergency boot device.
2.
Copy the existing configuration in the file
/config/juniper.conf.gz
from the switch to a
remote system, such as a server, or to an emergency boot device. For extra safety,
you can also copy the backup configurations (the files named
/config/juniper.conf. n
,
where n is a number from 0 through 9) to a remote system or to an emergency boot
device.
WARNING: The recovery installation process completely overwrites the
entire contents of the internal flash storage.
3.
Copy any other stored files to a remote system as desired.
To reinstall Junos OS:
1.
Insert the emergency boot device into the QFX Series device.
2.
Power cycle the QFX Series device.
The emergency boot device (external USB install media) is detected. At this time, you
can load the Junos OS from the emergency boot device onto the internal flash storage.
3.
The software prompts you with the following options:
Junos Snapshot Installer - (c) Juniper Networks 2013
Reboot
Install Junos Snapshot
[13.2-20131115_x_132_x51_vjunos.0Boot to host shell [debug]
4.
Select Install Junos to format the internal flash storage and install the Junos OS on
the emergency boot device onto the internal flash storage.
5.
The switch copies the software from the emergency boot device, occasionally
displaying status messages. Copying the software can take up to 12 minutes.
When the software is finished being copied from the emergency device to the QFX5100
switch, the QFX5100 switch the reboots from the internal flash storage on which the
227 Copyright © 2014, Juniper Networks, Inc.
Chapter 24: Restoring Junos OS