A vSphere cluster hosts a three-tier application. The cluster has 50% resources available. If a host in the cluster fails, the database server must be online before the application server, and the appli-cation server must be online before the Web server.
Which feature can be used to meet these requirements?
To meet the requirements of ensuring that the database server is online before the application server, and the application server is online before the Web server, the feature needed is vSphere HA Orchestrated Restart. This feature allows for the orchestration of VM restarts in a specific order, which is essential to ensure that dependencies are met during the restart process following a host failure in the cluster.
B https://www.vladan.fr/what-is-vmware-orchestrated-restart/
Pledian is incorrect, C is used when a host is restarted and the order in which VMs would restart, B refers to VMs that rely on each other that need rebooting in an order, see jennyka76's answer with a useful URL.
While both B and C can be used to control restart order, answer B makes more sense in the given scenario. NOTE: for folks using chatGPT to find answers, please triple-check them before posting :)
he correct answer is C, vSphere HA Restart Priority. vSphere HA Restart Priority allows you to specify the order in which virtual machines are restarted after a host failure. This can be used to ensure that critical virtual machines are restarted first. In the scenario described, the database server is the most critical virtual machine, followed by the application server, and then the Web server. You would therefore set the restart priority for the database server to 1, the application server to 2, and the Web server to 3. This would ensure that the database server is restarted first, followed by the application server, and then the Web server. This would minimize the impact of the host failure on the three-tier application
Duncan Epping describes perfectly .... ...restart orchestration is considered a hard rule. In other words: if one VM can’t be restarted when restart orchestration is used then the next batch will not start. https://www.yellow-bricks.com/2018/10/15/ha-futures-orchestrated-restart-restarting-and-restart-priority/
B is the correct answer. For option C the 3 VM's should be running on the same host.
Actually it could be c too if you set overrides. but B makes more sense^^
Selecting B, page 28 details some good info https://safe.menlosecurity.com/doc/docview/viewer/docN225BF690A82C0938649ed9c5b78d779381b45ffd2f4ce22996a86ee05903e9c2c8be86bafcd5