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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 18.2R3 for vSRX using J-Web (see J-Web) or the Junos Space Network Management Platform (see Junos Space).


Direct upgrade from any Junos OS Release 15.1X49 to Junos OS Release 18.x is not supported. You need to first upgrade from Junos OS Release 15.1X49 to 17.4 and then upgrade from Junos OS Release 17.4 to 18.x. Or, you can directly launch a new instance with Junos OS Release 18.2R3 image.

Upgrading Software Packages

To upgrade the software using the CLI:

  1. Download the Junos OS Release 18.2R3 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 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 18.2R3 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.


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

  6. You have successfully upgraded to Junos OS Release 18.2R3 for vSRX. Now 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.