A VM-Host affinity rule states that VM group "X" must run on hosts in group "Y".
If all ESXi hosts in group "Y" fail, which is the resulting behavior with vSphere HA enabled?
A. The virtual machines in group "X" will failover to hosts that do not belong to group "Y", but will vMotion back to hosts in group "Y" when they become available.
B. The virtual machines in group "X" will not failover to hosts that do not belong to group "Y".
C. This scenario is not possible because vSphere HA and DRS cannot work together.
D. The virtual machines in group "X" will only fail over to hosts that do not belong to group "Y" if they are marked as "High" VM Restart Prioritywithin vSphere HA.
B
https://pubs.vmware.com/vsphere-51/index.jsp?topic=%2Fcom.vmware.vsphere.resmgmt.doc%2FGUID-D2E5FBE2-E4BF-48B1-BF02-BF37AE9D5F21.html
DRS, vSphere HA, and vSphere DPM never take any action that results in the violation of required affinity rules (those where the virtual machine DRS group ‘must run on’ or ‘must not run on’ the host DRS group). Accordingly, you should exercise caution when using this type of rule because of its potential to adversely affect the functioning of the cluster. If improperly used, required VM-Host affinity rules can fragment the cluster and inhibit the proper functioning of DRS, vSphere HA, and vSphere DPM.
A number of cluster functions are not performed if doing so would violate a required affinity rule.
■DRS does not evacuate virtual machines to place a host in maintenance mode.
■DRS does not place virtual machines for power-on or load balance virtual machines.
■vSphere HA does not perform failovers.
■vSphere DPM does not optimize power management by placing hosts into standby mode.
from: https://www.mindthevirt.com/vmware-drs-rules-should-vs-must/
Must run on hosts in group
The VM Group must run on the hosts in this group. If the selected hosts are down, the VMs will be down and not be restarted on a different host.
If you have applications with special license agreements, you might have to use this option.
B is correct
https://pubs.vmware.com/vsphere-51/index.jsp?topic=%2Fcom.vmware.vsphere.resmgmt.doc%2FGUID-D2E5FBE2-E4BF-48B1-BF02-BF37AE9D5F21.html
DRS, vSphere HA, and vSphere DPM never take any action that results in the violation of required affinity rules (those where the virtual machine DRS group ‘must run on’ or ‘must not run on’ the host DRS group). Accordingly, you should exercise caution when using this type of rule because of its potential to adversely affect the functioning of the cluster. If improperly used, required VM-Host affinity rules can fragment the cluster and inhibit the proper functioning of DRS, vSphere HA, and vSphere DPM.
A number of cluster functions are not performed if doing so would violate a required affinity rule.
■DRS does not evacuate virtual machines to place a host in maintenance mode.
■DRS does not place virtual machines for power-on or load balance virtual machines.
■vSphere HA does not perform failovers.
■vSphere DPM does not optimize power management by placing hosts into standby mode.
from: https://www.mindthevirt.com/vmware-drs-rules-should-vs-must/
Must run on hosts in group
The VM Group must run on the hosts in this group. If the selected hosts are down, the VMs will be down and not be restarted on a different host.
If you have applications with special license agreements, you might have to use this option.
B
https://docs.vmware.com/en/VMware-vSphere/6.5/com.vmware.vsphere.avail.doc/GUID-E137A9F8-17E4-4DE7-B986-94A0999CF327.html
B
B
Restart priority has nothing to do with this.