Install, Upgrade, and Downgrade Software
Devices are delivered with Junos OS Evolved already installed on them. As new features and software fixes become available, you must upgrade Junos OS Evolved to use them. You can install software on devices that have either single or redundant routing engines. Before you install a software release on a device, you should make any necessary changes to the configuration and back up the current system.
Junos OS Evolved ensures that all Routing Engines (Routing Engines) and FPCs in the system
are running the same software version. When you issue the request system software add
image-name
operational mode command on the primary Routing
Engine, the system installs the new version of software on both Routing Engines. Once you
reboot the system after a software package installation, all the Routing Engines and FPCs in
the system run the new version of the software.
Junos OS Evolved supports storing multiple versions of software on the storage media. You can
view the installed versions on the device with the show system software list
operational mode command. Each version of the software is stored in a distinct area in the
/soft directory, ensuring that a software package installation does
not impact the other software versions installed in the system. We recommend you keep no more
than 5 versions of software in the system.
In Junos OS, you must first upgrade the software on the standby Routing Engine and then switch control to the standby Routing Engine to run the new software version. After you are sure the software upgrade on the original standby Routing Engine is successful, you can upgrade the original primary Routing Engine to the new software version and switch control back to the original primary Routing Engine. However, with Junos OS Evolved, you do not need to upgrade the standby Routing Engine first. You upgrade both Routing Engines using a single command issued on the primary Routing Engine.
During a successful installation, the installation package completely re-installs the existing software. It retains configuration files and similar information, such as secure shell and host keys, from the previous version. The previous software package is preserved in a separate area, and you can manually roll back to it if necessary. If the software installation fails for any reason, such as loss of power during the installation process, the system returns to the originally active installation when you reboot. For more background information on software installation, see Software Installation and Upgrade Overview (Junos OS Evolved).
Junos OS Evolved allows you to roll back to any of the releases stored in the system with the
request system software rollback image-name
operational
mode command. The system also stores with each release the last configuration that was running
when the release was running. Junos OS Evolved supports rolling back to an alternate image
with the currently-running configuration or with the saved configuration that corresponds to
the rollback software image, with the request system software rollback
with-old-snapshot-config
operational mode command.
If the system does not function properly after the upgrade and reboot, the previous version can be restored by rolling back to the previous version. See the roll back step in the Recover from a Failed Installation Attempt If the CLI Is Working procedure.
For dual-Routing Engine devices, if a Routing Engine inserted into the device has a different
software version, the new Routing Engine is kept out of the system. We recommend that you
configure the software to synchronize automatically to the new Routing Engine, by configuring
the auto-sw-sync enable
statement at the [edit system]
hierarchy level. When this configuration is present, the Routing Engine that is in the system
copies over all the images to the new Routing Engine and reboots the new Routing Engine so
that it automatically comes up with the correct software. You can also choose to synchronize
the software to the new Routing Engine manually each time you have to replace a Routing
Engine, by using the request system software sync all-versions
operational
mode command, which synchronizes the software versions and configurations. For more
information about replacing Routing Engines, see Replace a Routing Engine in a Dual-Routing Engine System.
Prepare to Install Software
Follow these steps to prepare to install your Junos OS Evolved software:
Prepare both Routing Engines to Join the System
For dual-Routing Engine devices, both Routing Engines must be participating in the system to be
able to install software on both Routing Engines. You must verify that both Routing
Engines are in the system and which software versions are currently running in the system.
You use the show system software list
, show system
nodes
, and show system alarms
operational mode commands to do so
and to determine what course of action to take if one of the Routing Engines is not
participating in the system.
Issue the show system software list
and show system nodes
commands on the primary Routing Engine to check the status of the Routing Engines. If
information about both re0
and re1
appear in the output,
and show a status of Status : online, apps-ready
in the output of the
show system nodes
command, both Routing Engines are operational, part
of the system, and are running the same software version. You can proceed to install the
software. See Install the Software Package on a Device with Redundant Routing Engines. For example:
user@host-re0> show system software list [...output truncated...] ------------------------------- node: re0 ------------------------------- Active boot device is primary: /dev/sda List of installed version(s) : '-' running version '>' next boot version after upgrade/downgrade '<' rollback boot version - junos-evo-install-ptx-x86-64-20.4R2.13-EVO - [2021-05-05 09:19:16] < junos-evo-install-ptx-x86-64-20.4R2.14-EVO - [2021-05-05 09:03:23] ------------------------------- node: re1 ------------------------------- Active boot device is primary: /dev/sda List of installed version(s) : '-' running version '>' next boot version after upgrade/downgrade '<' rollback boot version - junos-evo-install-ptx-x86-64-20.4R2.13-EVO - [2021-05-05 09:22:09] < junos-evo-install-ptx-x86-64-20.4R2.14-EVO - [2021-05-05 09:06:50] user@host-re0> show system nodes Node: fpc0 Node Id : 2201170739216 Node Nonce : 2632845278 Status : online, apps-ready Attributes : ASICS (Active), BT (Active), FABRIC_PFE (Active), FPC (Active), PIC (Active), TIMINGD_FPC (Active), MSVCSD (Active) Node: re0 Node Id : 2201170739204 Node Nonce : 1829978227 Status : online, apps-ready Attributes : FABRIC_CONTROL (Active), FABRIC_FCHIP_PARALLEL (Active), RE (Active), TIMINGD_RE (Active), MasterRE (Active), GlobalIPOwner (Active) Node: re1 Node Id : 2201170739205 Node Nonce : 3166228206 Status : online, apps-ready Attributes : FABRIC_CONTROL (Spare), FABRIC_FCHIP_PARALLEL (Spare), RE (Spare), TIMINGD_RE (Spare), BackupRE (Active)
If both Routing Engines are present, but the status of one Routing Engine is not Status :
online, apps-ready
, you need to take action to bring that Routing Engine into
the system. In these examples, re0
is the Routing Engine in the system
and re1
is the other Routing Engine that needs to join the system:
Install the Software Package on a Device with Redundant Routing Engines
Unlike Junos OS, Junos OS Evolved ensures all nodes in a system are running the same software version. In Junos OS Evolved, the device can contain multiple releases of the software simultaneously if enough space exists. If the device does not have enough space, you must delete an older image of the software before installing a new one. We recommend that you store no more than 5 versions of software on the device.
Before you install a new software release on a device, you should back up the current system. See Back Up and Recover Software with Snapshots.
Before you upgrade the software, you must prepare for the installation. See Prepare to Install Software.
The request system software add
operational mode command installs the software
on both the Routing Engines. This command does not modify the currently running software
stack. This command validates the current configuration using the new version of the
software. Once validation succeeds, the install process checks for sufficient storage on
both Routing Engines. Once the storage checks pass, the new software is installed on both
Routing Engines. You need to reboot the system to run the new software. The software
installation process only affects traffic for a short while; for more information, see
Table 1.
Tasks | Actions | Traffic Impact |
---|---|---|
Add the software | Validate the configuration, check for sufficient storage, install on both Routing Engines | None |
Verify the software installation | Show image that will be the current image after the system reboots | None |
Reboot the system | Reboot all Routing Engines and FPCs at the same time | Impacted; resumes after the system reboots |
Verify which software image is running | Show image running after reboot | None |
To upgrade the software on a device:
Install the Software Package on a Device with a Single Routing Engine
Before you install a new software release on a device, you should back up the current system. See Back Up and Recover Software with Snapshots.
In Junos OS Evolved, the device can contain multiple releases of the software simultaneously as long as the system has enough space. If the system does not have enough space, you must delete an older image of the software before installing a new one. We recommend that you store no more than 5 versions of software on the device.
Before you upgrade the software, you must prepare for the installation. See Prepare to Install Software.
To upgrade the software on a device:
See Also
Recover from a Failed Installation Attempt If the CLI Is Working
If a Junos OS Evolved installation fails, and the CLI is working, use one of these procedures to install Junos OS Evolved, depending upon the situation:
Replace a Routing Engine in a Dual-Routing Engine System
Junos OS Evolved ensures all nodes in a system are running the same software version.
If you insert a Routing Engine that has the same current software version as the primary Routing
Engine into the system, the new Routing Engine joins the system, and the configurations
and the other software versions automatically synchronize from the existing Routing Engine
to the new Routing Engine, even if you have not configured the
auto-sw-sync
statement.
If you insert a Routing Engine that has a different software version into the system and you have
not configured the auto-sw-sync enable
statement, the Routing Engine is
kept outside the system and the system generates a software mismatch alarm. The alarm
message displays the Routing Engine name and the version of software on the newly-inserted
Routing Engine, similar to the following: Software Version Mismatch on
re1:junos-evo-install-ptx-x86-64-20.4R2.6-EVO.
.
user@host-re0> show system alarms 2 alarms currently active Alarm time Class Description 2021-04-19 16:02:26 PDT Major Re1 Node unreachable 2021-04-19 16:04:46 PDT Major Software Version Mismatch on re1:junos-evo-install-ptx-x86-64-20.4R2.6-EVO
To clear the alarms and bring the Routing Engine into the system, manually synchronize the
primary Routing Engine to the new Routing Engine with the request system software
sync all-versions
operational mode command.
We recommend that you configure the auto-sw-sync enable
configuration statement
at the [edit system]
hierarchy level before inserting a new Routing
Engine into the system. When you do so, the Routing Engine in the system detects the
newly-inserted Routing Engine and automatically synchronizes the software to the new
Routing Engine. All images are synchronized to the new Routing Engine and the system
reboots the newly-inserted Routing Engine. When the newly-inserted Routing Engine comes
back up, it joins the system. Each software image has the configuration used when the
image ran stored with it. The configuration associated with the current running image is
synchronized from the primary Routing Engine to the backup Routing Engine. Configurations
stored with the rollback and other images are also synchronized to the backup Routing
Engine when you configure the auto-sw-sync enable
statement on the
primary Routing Engine.
To replace a Routing Engine in a dual-Routing Engine system:
Not Enough Disk Space for Software Installation
The software installation process requires a certain amount of unused disk space. If the system does not have enough space, you receive an error message similar to the following:
WARNING: The /soft filesystem is low on free disk space.
WARNING: This package requires 1075136k free, but there is only 666502k available.
If you need to create enough disk space for the software installation to be successful, you can do the following:
- Identify and delete older images by using the
show system software list
andrequest system software delete
operational mode commands. - Identify and delete unnecessary files by using the
show system storage
andrequest system storage cleanup
operational mode commands.
For more information on how to create enough disk space for a software installation, see Ensure Sufficient Disk Space for Upgrades.