Performing A Recovery Installation - Juniper QFX5110 Series Hardware Documentation

Performing a Recovery Installation

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.
Starting in Junos OS Release 14.1, you can also use a system snapshot as a bootup option when your Junos
OS or configuration is damaged. The system snapshot feature takes a "snapshot" of the files currently used
to run the device—the complete contents of the /config directories, which include the running Juniper
Networks Junos OS, the active configuration, and the rescue configuration, as well as the host OS—and
copies all of these files into an external USB flash drive. See Understanding How to Back Up an Installation
on Switches.
NOTE: System snapshot is not supported on QFX10002 switches.
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
Emergency Boot Device for QFX Series Switches" on page 579
emergency boot device.
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:
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. Reboot the QFX Series device.
The recovery installation process completely overwrites the entire
"Creating an
for information on how to create an
581