If one of the hosts in the cluster fails, the vSphere HA feature restarts a VM on another host that has enough free resources. Dell EMC strongly recommends that you enable this feature in a vSphere cluster with SAP HANA. The SAP HANA service autostart feature must be enabled in the SAP HANA software. You can enable the autostart feature at the time of the SAP HANA installation or by setting the autostart option to 1 in the /hana/shared/<SID>/profile/<SID>_HDB<InstNo>_<hostname> file. The minimum vSphere HA settings must be in place, as shown in the following figure:
Figure 6. vSAN cluster HA settings
The SAP HANA service autorestart watchdog function, which automatically detects a failure and restarts the corresponding SAP HANA process (nameserver, index server, and so on), monitors the SAP HANA application and the associated services within a VM. The VMware HA monitoring feature “Guest not heartbeating” restarts the guest operating system of the VM as well as SAP HANA on the same host. The monitoring feature also handles operating system crashes as long as the SAP HANA autostart options are enabled.
Enable the heartbeat monitoring feature when vSphere HA is enabled. Dell EMC recommends setting Heartbeat monitoring sensitivity to High, as shown in the following figure:
Figure 7. vSphere settings for VM monitoring
VMware Tools must be installed and running in the VM. You can install VMware Tools as part of the operating system open-vm-tools or by using the vSphere web client and selecting Guest OS > Install VMware Tools in the VM context menu.