Juniper QFX Series User Manual

Performing a Recovery Installation on a QFX3500 Device and QFX3008-I Interconnect
Device
If Junos OS on your device 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
device.
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.
2. Copy the existing configuration in the file /config/juniper.conf.gz from the device 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 QFX3500 device..
2. Reboot the QFX3500 device.
NOTE: Do not power off the device if it is already on.
[edit system]
user@device> request system reboot
3. When the software prompts you with the following question, type y:
WARNING: The installation will erase the contents of your disk. Do you
wish to continue (y/n)? y
4. The device copies the software from the emergency boot device, occasionally
displaying status messages. Copying the software can take up to 10 minutes.
When the device is finished copyingthe software, you are presented with the following
prompt:
*** Mon Mar 21 21:08:41 UTC 2011 ***
Installation successful..
409Copyright © 2012, Juniper Networks, Inc.
Chapter 33: Restoring Junos OS

Juniper QFX Series Specifications

General

Category	Switch
Series	QFX
Form Factor	1U, 2U, and modular chassis options
Power Supply	Redundant, hot-swappable power supplies
Cooling	hot-swappable fans
Virtual Chassis	Supported on certain models
Typical Use	Data center, cloud
Operating System	Junos OS
Management	CLI
Key Features	High performance, low latency, automation
Latency	Sub-microsecond latency
Port Density	Varies by model (e.g., QFX5100: up to 48x10GbE + 6x40GbE)