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Migration, Upgrade, and Downgrade Instructions

This section contains information about how to upgrade Junos OS for vSRX using the CLI. Upgrading or downgrading Junos OS can take several hours, depending on the size and configuration of the network.

You also can upgrade to Junos OS Release 22.2R1 for vSRX using J-Web (see J-Web) or the Junos Space Network Management Platform (see Junos Space).

Starting in Junos OS release 21.2R1, all Junos OS products which were previously running on FreeBSD 11.x based Junos OS are migrated to FreeBSD 12.x based Junos OS, except EX4400. Starting with Junos OS release 21.3R1, EX4400 platforms are migrated to FreeBSD 12.x based Junos OS.

Direct upgrade of vSRX from Junos OS 15.1X49 Releases to Junos OS Releases 17.4, 18.1, 18.2, 18.3,18.4, 19.1, 19.2 and 19.4 is supported.

The following limitations apply:

  • Direct upgrade of vSRX from Junos OS 15.1X49 Releases to Junos OS Release 19.3 and higher is not supported. For upgrade between other combinations of Junos OS Releases in vSRX and vSRX 3.0, the general Junos OS upgrade policy applies.

  • The file system mounted on /var usage must be below 14% of capacity.

    Check this using the following command:

    Using the request system storage cleanup command might help reach that percentage.

  • The Junos OS upgrade image must be placed in the directory /var/host-mnt/var/tmp/. Use the request system software add /var/host-mnt/var/tmp/<upgrade_image>

  • We recommend that you deploy a new vSRX virtual machine (VM) instead of performing a Junos OS upgrade. That also gives you the option to move from vSRX to the newer and more recommended vSRX 3.0.

  • Ensure to back up valuable items such as configurations, license-keys, certificates, and other files that you would like to keep.


For ESXi deployments, the firmware upgrade from Junos OS Release 15.1X49-Dxx to Junos OS releases 17.x, 18.x, or 19.x is not recommended if there are more than three network adapters on the 15.1X49-Dxx vSRX instance. If there are more than three network adapters and you want to upgrade, then we recommend that you either delete all the additional network adapters and add the network adapters after the upgrade or deploy a new vSRX instance on the targeted OS version.

Upgrading Software Packages

To upgrade the software using the CLI:

  1. Download the Junos OS Release 22.2R1 for vSRX .tgz file from the Juniper Networks website. Note the size of the software image.

  2. Verify that you have enough free disk space on the vSRX instance to upload the new software image.

  3. Optionally, free up more disk space, if needed, to upload the image.


    If this command does not free up enough disk space, see [SRX] Common and safe files to remove in order to increase available system storage for details on safe files you can manually remove from vSRX to free up disk space.

  4. Use FTP, SCP, or a similar utility to upload the Junos OS Release 22.2R1 for vSRX .tgz file to /var/crash/corefiles/ on the local file system of your vSRX VM. For example:

  5. From operational mode, install the software upgrade package.

    If no errors occur, Junos OS reboots automatically to complete the upgrade process. You have successfully upgraded to Junos OS Release 22.2R1 for vSRX.


    Starting in Junos OS Release 17.4R1, upon completion of the vSRX image upgrade, the original image is removed by default as part of the upgrade process.

  6. Log in and use the show version command to verify the upgrade.

Validating the OVA Image

If you have downloaded a vSRX .ova image and need to validate it, see Validating the vSRX .ova File for VMware.

Note that only .ova (VMware platform) vSRX images can be validated. The .qcow2 vSRX images for use with KVM cannot be validated the same way. File checksums for all software images are, however, available on the download page.

Upgrade and Downgrade Support Policy for Junos OS Releases and Extended End-Of-Life Releases

Support for upgrades and downgrades that span more than three Junos OS releases at a time is not provided, except for releases that are designated as Extended End-of-Life (EEOL) releases. EEOL releases provide direct upgrade and downgrade paths—you can upgrade directly from one EEOL release to the next EEOL release even though EEOL releases generally occur in increments beyond three releases.

You can upgrade or downgrade to the EEOL release that occurs directly before or after the currently installed EEOL release, or to two EEOL releases before or after. For example, Junos OS Releases 19,4, 20.2, and 20.4 are EEOL releases. You can upgrade from Junos OS Release 19.4 to Release 20.1, 20.2, 20.3 or to 20.4. Or from Junos OS Releases 20.2, 20.3 or 20.4 to Release 22.2.

You cannot upgrade directly from a non-EEOL release to a release that is more than three releases ahead or behind. To upgrade or downgrade from a non-EEOL release to a release more than three releases before or after, first upgrade to the next EEOL release and then upgrade or downgrade from that EEOL release to your target release.

For more information about EEOL releases and to review a list of EEOL releases, see

For information about software installation and upgrade, see the Installation and Upgrade Guide.