Help us improve your experience.

Let us know what you think.

Do you have time for a two-minute survey?

 
ON THIS PAGE
 

Downgrading Software on a QFabric System

Starting in Junos OS Release 14.1, if a software upgrade or configuration changes has made the QFabric system unstable or inoperable, you can rollback or downgrade to a previous version of software and configuration. The software and configuration that you rollback to is called a restore-point. The restore-point is stored in a dedicated partition. You can create a checksum (MD5 hash) for the partition in which the restore-partition is stored and verify the integrity of the restore-point partition.

Note:

The ability to downgrade the software does not replace the existing back up and restore functionality.

If possible, perform the following steps before you perform the recovery installation:

  1. Ensure that you have an emergency boot device (for example, an external USB flash drive) for each of your Director devices to use during the recovery installation.

    You can either use the external USB flash drive containing the software supplied by Juniper Networks, or you can use an external USB flash drive supplied by Juniper Networks on which you install the QFabric system install media.

  2. Because the recovery installation process completely overwrites the entire contents of the Director device, make sure you back up any configuration files and initial setup information on a different external USB flash drive before you begin a recovery installation. You will need to restore this information as part of recovery process.

    Use the request system software configuration-backup command to back up your configuration files and initial setup information:

Note:

To recover the Director group, you must upgrade both Director devices in parallel. If you are recovering only one Director device in a Director group, and the software version will remain the same between the two Director devices, make sure that the other Director device is powered on and operational. If the software version of the Director device you are recovering will be different, make sure that the other Director device is powered off and is not operational.

(Optional) Creating an Emergency Boot Device Using a Juniper Networks External Blank USB Flash Drive

If you do not have an external USB flash drive preloaded with the software from Juniper Networks to use as an emergency boot device, you can create your own, using a blank external USB flash drive provided by Juniper Networks. Download the install media from the Juniper Networks Support website onto your UNIX workstation, uncompress and untar the software, and then burn the software image onto your Juniper Networks external USB (4-gigabyte) flash drive. Make sure you create two emergency boot devices, one for each Director device, so you can perform a recovery installation in parallel.

  1. Using a Web browser, navigate to the https://www.juniper.net/support .
  2. Click Download Software.
  3. In the Switchingbox, click Junos OS Platforms.
  4. In the QFX Series section, click the name of the platform for which you want to download software.
  5. Click the Software tab and select the release number from the Release drop-down list.
  6. Select the complete install media you want to download in the QFabric System Install Media section.

    A login screen appears.

  7. Enter your name and password and press Enter.
  8. Read the End User License Agreement, click the I agree radio button, and then click Proceed.
  9. Log in and save the install media file to your UNIX workstation.
  10. Use FTP to access the UNIX workstation where the install media resides.
  11. When prompted, enter your username and password.
  12. Make sure you are in binary mode by entering binary at the prompt.
  13. Use the get command to transfer the installation package from the FTP host to your UNIX workstation.
  14. Close the FTP session:
  15. Untar the install-media-qfabric-<version> .img.tgz file on your UNIX workstation.
  16. Insert a blank external USB (4-gigabyte) flash drive supplied by Juniper Networks into your UNIX workstation.
  17. Burn the software image you just downloaded to your UNIX workstation onto your external USB flash drive using the dd command:
  18. Perform the steps in Performing a Recovery Installation Using a Juniper Networks External USB Flash Drive with Preloaded Software to continue with the recovery installation.

Performing a Recovery Installation Using a Juniper Networks External USB Flash Drive with Preloaded Software

This procedure describes how to perform a recovery installation using an external USB flash drive that contains Junos OS software.

Note:

Since the recovery installation process completely overwrites the entire contents of the Director device, you will need to restore the required configuration files and initial setup information. The following procedure assumes you previously saved these backup files with the request system software configuration-backup command. Ensure that you have these backup files available on an external USB flash drive before you perform the following steps.

  1. Insert the external USB flash drive into the Director device.
  2. Perform one of the following tasks:

    • If you have access to the default partition, reboot the Director device by issuing the request system reboot director-group command.

    • If you do not have access to the default partition, power cycle the Director device.

    The following menu appears on the Director device console when the Director device boots up:

  3. Type install and then press Enter to install the software on the Director device.

    Once the installation process is complete, the Director device reboots, and the following menu appears on the Director device console:

  4. Press Enter.

    The Director device reboots from the local disk on which the software was just installed.

  5. Log in as root on the Director device.

    The following menu appears on the Director device console:

  6. Enter n to bypass the initial setup script and enter the Director device root directory, where you can mount the external USB flash drive containing the configuration files and initial setup information.
  7. Issue the ls /mnt command to list the mount directory.
  8. Issue the mkdir command to create a directory within the mount directory.
  9. Issue the mount /dev/sdb2 /mnt/myusb/ command to mount the external USB flash drive to the local drive of the Director device.
  10. Issue the ls -la /mnt/myusb/ command to verify the contents of your mounted external USB flashdrive.
  11. Exit the Director device and log back in as root on the Director device.

    The following menu appears:

  12. Enter y to continue.
  13. Enter y and specify the path to the backup configuration file located on the external USB flash drive.

    The following messages appear:

    The Director device reboots from the local disk on which the software was just installed. Exit the Director device session and log in to the QFabric default partition CLI.

  14. Issue the request system software configuration-restore command and specify the path to the backup configuration file located on the external USB flash drive to load the previously saved QFabric system configuration.
  15. From the default partition, issue the request system reboot node-group all command to reboot all of the Node groups in the QFabric system to ensure that all Node devices are running the same version of software as the Director-group.
  16. From the default partition, issue the request system reboot fabric command to reboot the Interconnect devices and the other components in the fabric in the QFabric system to ensure that Interconnect devices are running the same version of software as the Director group.
  17. Log in to the default partition and issue the show version component all command to verify that all components are running the same version of software.
Release History Table
Release
Description
14.1
Starting in Junos OS Release 14.1, if a software upgrade or configuration changes has made the QFabric system unstable or inoperable, you can rollback or downgrade to a previous version of software and configuration.