SUM Takeover at Downtime Phase - SLES Cluster disabled

[richard_howard]

As a part of our S/4Hana 2021 Upgrade, we will upgrade the OS to SLES 15.

• Shutdown secondary node
• Upgrade server to SLES 15 SP4
• At this point, the Cluster will not work with one node on SLES 12 and the other on SLES 15
• Resume HSR
• Start the Uptime Phase

When we get to the Downtime Phase, we need to failover to the secondary node so that the primary node can be upgraded to SLES 15 in parallel with our downtime processing. The SLES High Availability is not available as mentioned above.

Does SUM handle the takeover to the secondary node? Do we run any kind of manual task at the OS that the Cluster would normally handle?

[AtulKumarJain]

Hi Richard,

It looks good approach, I would advise here please validate this approach listed in the SUM guide for HA

For more information about this feature and how to check whether the automatic maintenance mode is available, see SAP Note

2464065 .

1. If necessary, you change your HA system con􀁆guration and clean up pro􀁆les.

For more information, see section Preparing the Update of Distributed and High Availability Systems.

2. You start the Software Update Manager.

3. The Software Update Manager checks the pro􀁆le directory. If the ASCS instance is installed on a different host name, the

tool assumes that the update is performed in a distributed or HA environment.

4. If prompted, you install a temporary license key in the shadow system and in the system during downtime. For information

about license keys, see https://support.sap.com/licensekey

5. If you are running the ASCS instance on a separate host, and the operating system on this host is different from that on the

primary application server instance, at the end of the downtime you are prompted to install the latest SAP kernel on the

separate host with the ASCS instance

BR

Atul