Hello binhbdq
Welcome to Communities.
If the compute resource (Host) that a VM is running on becomes unavailable then the VM has to be re-registered on another host that has access to the backing storage - this is the same behaviour whether using vSAN or VMFS for storage, e.g. you cannot live vMotion a VM from a host that is down. If you require a solution whereby VMs stay up in the event that the host they are running on goes down then consider configuring vSphere Fault Tolerance for these particular VMs.
Bob
