Manual Chapter : Downgrade Software

Applies To:

  • F5OS-C

    1.6.0

back-action VELOS Systems: Software Installation and Upgrade

Updated Date: 04/22/2026

Downgrade Software

Before you downgrade the F5OS software on your system:

  • Back up your system controller, chassis partition, and tenant configurations. For more information, see “Back up system configurations from the webUI” in VELOS Systems: Administration and Configuration at support.f5.com/csp/knowledge-center/software/F5OS.
  • Export your backups to a safe, off-unit location.
  • Upload system controller and chassis partition image files to each chassis before the scheduled maintenance window to minimize the time needed to downgrade.
  • Make sure the F5OS version you are downgrading to is still under End of Software Development/Technical Support (EoSD/EoTS); see KB article https://my.f5.com/manage/s/article/K21501912 for F5OS software lifecycle information.
  • Make sure your tenant software versions are compatible with the F5OS version you are downgrading to; see KB article https://my.f5.com/manage/s/article/K86001294 for the F5OS and tenant software compatibility matrix.

You can use the system controller CLI to perform a downgrade of F5OS software to an earlier version.

Before you downgrade your system controller software, verify that you have downloaded and imported the F5OS-C system controller image files from downloads.f5.com.

If necessary, you can return to a previous version of F5OS-C software on a VELOS system controller from the CLI. This method downgrades only one system controller at a time. When the installation succeeds, the other system controller updates to the previous software version.

  1. Connect to the system using a management console or console server.

    Note: The default baud rate and serial port configuration is 19200/8-N-1.

  2. Log in to the command line interface (CLI) of the system controller using an account with admin access.

    When you log in to the system, you are in user (operational) mode.

  3. Verify that the system controller image you want to install is listed, and the status is ready.

    show image controller

    This verifies that the ISO is imported properly to the image server on the system controllers, and the system controllers can access these images when the blade reboots.

    A summary similar to this excerpt displays:

    syscon-1-active# show image controller
VERSION OS                                             IN
CONTROLLER   CONTROLLER  STATUS  DATE        SIZE      USE
--------------------------------------------------------------
1.5.0-6789   1           ready   2022-09-28  836.63MB  false
1.6.0-7890   1           ready   2022-12-09  824.75MB  true


VERSION
SERVICE                                              IN
CONTROLLER   CONTROLLER  STATUS  DATE        SIZE    USE
--------------------------------------------------------------
1.5.0-6789   1           ready   2022-09-28  3.14GB  false
1.6.0-7890   1           ready   2022-12-09  3.51GB  true


VERSION ISO                                          IN
CONTROLLER   CONTROLLER  STATUS  DATE        SIZE    USE
--------------------------------------------------------------
1.5.0-6789   1           ready   2022-12-09  5.68GB  false
1.6.0-7890   1           ready   2022-09-28  4.94GB  true


VERSION OS                                             IN
CONTROLLER   CONTROLLER  STATUS  DATE        SIZE      USE
--------------------------------------------------------------
1.5.0-6789   2           ready   2022-12-09  836.63MB  false
1.6.0-7890   2           ready   2022-09-28  824.75MB  true


VERSION
SERVICE                                              IN
CONTROLLER   CONTROLLER  STATUS  DATE        SIZE    USE
--------------------------------------------------------------
1.5.0-6789   2           ready   2022-12-09  3.14GB  false
1.6.0-7890   2           ready   2022-09-28  3.51GB  true


VERSION ISO                                          IN
CONTROLLER   CONTROLLER  STATUS  DATE        SIZE    USE
--------------------------------------------------------------
1.5.0-6789   2           ready   2022-12-09  5.68GB  false
1.6.0-7890   2           ready   2022-09-28  4.94GB  true

  4. Change to config mode.

    config

    The CLI prompt changes to include (config).

  5. Set the ISO version to the new version.

    system image set-version iso-version <*version*>

    Note: By default, you will be prompted to confirm the downgrade.

    This example shows downgrading the ISO version:

    syscon-1-active(config)# system image set-version iso-version 1.5.0-6789

  6. When the compatibility check succeeds, type yes to proceed with the installation process.

    A summary similar to this excerpt displays:

    syscon-1-active(config)# system image set-version iso-version 1.5.0-6789
Updating the running chassis controller software version may temporarily degrade system 
performance and manageability. Proceed? [yes/no]:
response Controller iso version has been set


Controller will reboot here, wait for reboot to complete and services to come up. Check 
controller networking, cluster status, partition status

The selected software version installs on the standby system controller, while the active system controller maintains production functionality of the chassis. After a successful installation, the active system controller reboots and switches to standby. Traffic is interrupted briefly during the failover from one system controller to the other, and you will have to log in again after failover occurs. The downgrade then installs on the other system controller. If, for any reason, the installation is not successful, the system reverts to the last working software version on both system controllers.

After you complete a downgrade of the system controller software, you downgrade the chassis partition to the same software version.

Before you downgrade your chassis partition software, verify that you have downloaded and imported the F5OS-C chassis partition image files from downloads.f5.com.

If necessary, you can return to a previous version of F5OS-C software on a VELOS chassis partition. This method downgrades only one blade in a chassis partition at a time and might cause an outage on any running tenants. When the installation succeeds, the remaining blades in the chassis partition update to the selected software version.

  1. Connect to the system using a management console or console server.

    Note: The default baud rate and serial port configuration is 19200/8-N-1.

  2. Log in to the command line interface (CLI) of the system controller using an account with admin access.

    When you log in to the system, you are in user (operational) mode.

  3. Verify that the image you want to install is listed, and the status is ready.

    show image partition state

    This verifies that the ISO is imported properly to the image server on the system controllers, and the system controllers can access these images when the blade reboots. The imported file replicates automatically to the standby controller.

    A summary similar to this excerpt displays:

    syscon-1-active# show image partition state
VERSION OS                                             IN
PARTITION   CONTROLLER  STATUS  DATE        SIZE       USE    NAME  ID
-----------------------------------------------------------------------------------------
1.5.0-6789  1           ready   2022-09-28  783.79MB   false
1.6.0-7890  1           ready   2022-12-09  783.99MB   true


 services service 1.6.0-7890
  controller 1
  status     ready
  date       2022-12-09
  size       1.79GB
  in-use     true
 services service 1.5.0-6789
  controller 1
  status     ready
  date       2022-09-28
  size       1.80GB
  in-use     false
NAME     ID
-------------
default  1
...

  4. Change to config mode.

    config

    The CLI prompt changes to include (config).

  5. Set the ISO version for the chassis partition so that its member blades are downgraded.

    partitions partition <*name*> set-version iso-version <*version*>

    Note: By default, you will be prompted to confirm the downgrade.

    This example shows downgrading the ISO version on the default chassis partition:

    syscon-1-active(config)# partitions partition default set-version iso-version 1.5.0-6789

  6. When the compatibility check succeeds, enter yes to proceed with the installation process.

    A summary similar to this excerpt displays:

    syscon-1-active(config)# partitions partition default set-version iso-version 1.5.0-6789
Partition database compatibility check succeeded.
Changing running partition software version will interrupt tenant operation. Proceed? [yes/no]: yes
result Version update successful.

The selected chassis partition downgrades to the specified version. The blades might reboot, depending on the changes in the install. After a successful downgrade, the downgrade installs on the remaining blades in that chassis partition. If, for any reason, the downgrade is not successful, the system reverts to the last working software version on the chassis partition.

You can use the system controller webUI to perform a downgrade of F5OS software to an earlier version.

Before you downgrade your system controller software, verify that you have downloaded and imported the F5OS-C system controller image files from downloads.f5.com.

If necessary, you can return to a previous version of F5OS-C software on a VELOS system controller from the system controller webUI. This method downgrades only one system controller at a time. When the installation succeeds, the other system controller updates to the previous software version.

  1. Log in to the VELOS system controller webUI using an account with admin access.

  2. On the left, click SYSTEM SETTINGS > Controller Management.

  3. In the Update Software section, for Update System Controller Software, select Bundled to install a full F5OS-C version release.

  4. For ISO Image, select the software image version.

  5. Leave the advanced options hidden.

  6. Click Save.

The selected software version installs on the standby system controller, while the active system controller maintains production functionality of the chassis. After a successful installation, the active system controller reboots and switches to standby. Traffic is interrupted briefly during the failover from one system controller to the other, and you will have to log in again after failover occurs. The downgrade then installs on the other system controller. If, for any reason, the installation is not successful, the system reverts to the last working software version on both system controllers.

After you complete a downgrade of the system controller software, you downgrade the chassis partition to the same software version.

Before you downgrade your chassis partition software, verify that you have downloaded and imported the F5OS-C chassis partition image files from downloads.f5.com.

If necessary, you can return to a previous version of F5OS-C software on a VELOS chassis partition from the system controller webUI. This method upgrades only one blade in a chassis partition at a time and might cause an outage on any running tenants. When the installation succeeds, the remaining blades in the chassis partition update to the selected software version.

  1. Log in to the VELOS system controller webUI using an account with admin access.

  2. On the left, click CHASSIS PARTITIONS.

    The Chassis Partitions screen opens.

  3. In the Partition list, select the chassis partition that you want to downgrade.

  4. Click Edit.

  5. In the Partition Image section, select Bundled to install an ISO image.

  6. In the Partition Image section, for ISO Image, select the software image version

  7. Click Save.

The selected chassis partition downgrades to the specified version. The blades might reboot, depending on the changes in the install. After a successful downgrade, the downgrade installs on the remaining blades in that chassis partition. If, for any reason, the downgrade is not successful, the system reverts to the last working software version on the chassis partition.