Abstract: A failover guaranty estimator module performs a proof by contradiction method showing that a cluster failover guaranty can be met for the cluster. For potential failures for which failover is guaranteed, the method assumes a particular host set of one or more hosts fails, leaving one or more working hosts. The method performs a per-failure host set method for the failure host set. The per-failure host set method determines an amount of memory usage within each working host of the assumed working host set that would guaranty that a largest of the virtual machines in the failure host set would be orphaned. The per-failure host set method determines if the virtual machines in the failure set, other than the largest virtual machine in that set, would force the determined amount of memory usage within working hosts, resulting in, the failover guaranty not being met.

Abstract: A failover guaranty estimator module performs a proof by contradiction method showing that a cluster failover guaranty can be met for the cluster. For potential failures for which failover is guaranteed, the method assumes a particular host set of one or more hosts fails, leaving one or more working hosts. The method performs a per-failure host set method for the failure host set. The per-failure host set method determines an amount of memory usage within each working host of the assumed working host set that would guaranty that a largest of the virtual machines in the failure host set would be orphaned. The per-failure host set method determines if the virtual machines in the failure set, other than the largest virtual machine in that set, would force the determined amount of memory usage within working hosts, resulting in, the failover guaranty not being met.