1-Download the software package.
2-(Optional) Back up the current software configuration to a second storage option. See the Junos OS Installation and Upgrade Guide for instructions on performing this task.
3-(Optional) Copy the software package to the switch. We recommend that you use FTP to copy the file to the /var/tmp directory.
This step is optional because Junos OS can also be upgraded when the software image is stored at a remote location. These instructions describe the software upgrade process for both scenarios.
4-Install the new package on the switch:
user@switch> request system software add package
Replace package with one of the following paths:
For a software package in a local directory on the switch—/var/tmp/package.tgz.
For a software package on a remote server:
where package.tgz is, for example, jinstall-ex-4200-9.4R1.8-domestic-signed.tgz.
Include the optional member option to install the software package on only one member of an EX4200 Virtual Chassis:
user@switch> request system software add source member member-id reboot
5-Reboot to start the new software:
user@switch> request system reboot
6-After the reboot has completed, log in and verify that the new version of the software is properly installed:
user@switch> show version
7-To ensure that the resilient dual-root partitions feature operates correctly, execute the following command to copy the new Junos OS image into the alternate root partition:
user@switch> request system snapshot slice alternate
To update the alternate root partitions on all members of a Virtual Chassis, use this command:
user@switch> request system snapshot slice alternate all-members