Fault tolerance method and system for virtual machine group

A fault tolerance method for a virtual machine group, applicable to a fault tolerance system, and comprising:

• establishing fault tolerance backup connections of a plurality of primary virtual machines between a virtual machine hypervisor of at least one primary host and a virtual machine hypervisor of at least one backup host to perform fault tolerance backups of the primary virtual machines, wherein the primary virtual machines are included in a fault tolerance group;
• and
• when a synchronizer determines that a failover of at least one first virtual machine among the primary virtual machines in the fault tolerance group is being performed,
• informing, by the synchronizer, to perform a failover of one or more other remaining primary virtual machines among the primary virtual machines in the fault tolerance group, or
• informing, by the synchronizer, to return the one or more other remaining primary virtual machines among the primary virtual machines in the fault tolerance group back to a last fault tolerance backup state of each and continue performing the fault tolerance backups of the other remaining primary virtual machines,
• wherein the fault tolerance system comprises the at least one primary host, the at least one backup host, and the synchronizer, wherein the synchronizer is connected to the at least one primary host and the at least one backup host,
• wherein the at least one primary host runs the primary virtual machines, wherein the at least one backup host runs a plurality of backup virtual machines, and wherein the primary virtual machines in the fault tolerance group correspond to the backup virtual machines when performing the fault tolerance backups.