Customers may be advised to install the latest supported os-package before staging certain Junos OS software upgrades.

• Many software installation and upgrade problems can be caused by limitations or defects in the package-management software of the currently running Junos OS release performing the installation, rather than by the new Junos OS release being installed.
• The os-package provides an updated version of the Junos OS package-management system that can be installed on the currently running system before performing an upgrade.
• Installing os-package does not require a reboot. Once installed, the updated package-management functionality is available for use during the planned software upgrade.

For some major FreeBSD transitions, a sufficiently recent os-package may also be required to support functions performed during the upgrade, including configuration validation.

Important

Always use the latest supported os-package appropriate for the source Junos OS release when an os-package update is required.

Do not assume that an os-package previously installed on the device is sufficiently recent for a new upgrade.

What is os-package?

os-package is a standalone update to the Junos OS package-management system.

Unlike a normal Junos OS software upgrade, which replaces the software running after the upgrade is completed, os-package updates the package-management functionality of the currently running Junos OS release.

This is useful when the existing Junos OS release has package-management limitations that could prevent it from correctly staging, validating, or installing a newer release.

For example:

Currently running Junos OS
→ install current os-package
→ updated package-management functionality becomes available
→ stage and validate the target Junos OS release
→ complete the Junos OS upgrade

The package is architecture-neutral and can be installed without rebooting the system.

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Why might os-package be required?

The software responsible for installing a Junos OS upgrade is initially the software already running on the device.

Consequently, an upgrade can encounter a problem even when the target Junos OS image itself is correct.

os-package provides updated package-management functionality to the currently running Junos OS release so that known package-management issues can be addressed before the upgrade is attempted.

It can also provide package-management functionality required for transitions between major FreeBSD versions.

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BSD12 to BSD15 upgrades

For applicable upgrades from BSD12-based Junos OS releases to BSD15-based Junos OS releases, configuration validation may require the os-forward-compat-12 compatibility package.

os-forward-compat-12 provides additional system-call support that allows components of the BSD15-based target release that are required for configuration validation to execute while the device is still running the BSD12 kernel.

A sufficiently recent os-package on the source Junos OS release provides the package-management functionality required to automatically use os-forward-compat-12 when configuration validation requires it.

For additional information about os-forward-compat-12, including package availability and applicable upgrade behavior, see KB109399 [juniper.net]: os-forward-compat-12 package description.

NOTE: It only takes a few seconds to run and does not need a reboot.

NOTE: Do not add "os-package" when there is already a 'pending' set, else you will get no benefit from "os-package". Thus, if you see the following notice after adding "os-package", follow step #3

NOTICE: 'pending' set will be activated at next reboot...

3. If the above NOTICE is seen, perform the steps below