Upgrading RHEL From 8 to 9

To attempt an in-place OS upgrade from RHEL 8 to RHEL 9, follow these steps:

1. Create a full backup of all databases.

2. Stop MarkLogic Server for the entire cluster.

3. Upgrade the OS from RHEL 8 to 9. Follow the standard upgrade procedure for MarkLogic Server along with the RHEL upgrade procedure, Upgrading From RHEL 8 to RHEL 9. According to the RHEL documentation, these are the supported in-place upgrade paths for the OS:

   Source OS	Target OS
   RHEL 8.8	RHEL 9.2
   RHEL 8.10	RHEL 9.4

4. Upgrade MarkLogic Server to version 11.3.1 or higher using the RHEL 9 installer in the upgraded machine as described in Upgrading From Previous Releases. In some cases, an in-place upgrade of RHEL will not retain all the applications in the previous systems. See Appendix: Linux Packages regarding dependencies and required libraries before upgrading MarkLogic Server.