You can install Administration Server version 15.3 on every Kaspersky Security Center Linux failover cluster node where the Administration Server with an earlier version is installed (starting from version 14). When upgrading to version 15.3, all data and settings from the previous version of Administration Server are preserved.
If you previously installed Kaspersky Security Center Linux on devices locally, you can also upgrade Kaspersky Security Center Linux on these devices by using the installation file or through backup.
To upgrade Kaspersky Security Center Linux on the Kaspersky Security Center Linux failover cluster nodes:
$ sudo yum install ./ksc64-<version number>-<build number>.x86_64.rpm
$ sudo apt-get install ./ksc64_<version number>-<build number>_amd64.deb
After the command has been successfully executed, the /opt/kaspersky/ksc64/lib/bin/setup/postinstall.pl script is created. The message about that is displayed in the terminal.
Installation of the application on your device will continue after you have entered 'Y' twice.
The picture below shows the last two steps.

Accepting the terms of the EULA and the Privacy Policy, and selecting the installation mode in the command-line terminal
Next, the script configures and finishes upgrading the Administration Server. During the upgrade, you cannot change the Administration Server settings adjusted before the upgrade.
At step 6, enter '3' to select the node.
Note that you can start the cluster on any node. If you start the cluster on the passive node, it becomes the active node.
We recommend that you upgrade the Network Agent for Linux to the same version as Kaspersky Security Center Linux.
After completion of the remote installation task, the Network Agent version is upgraded.
Run the following commands on Linux-based assets to remove dependencies that are no longer needed:
apt-get -y autoremoveapt -y autoremovednf autoremoveyum autoremoveAs a result, you installed the Administration Server of the latest version on the Kaspersky Security Center Linux failover cluster nodes.