The embodiment of the invention provides a disaster tolerance method and disaster tolerance
system, so that a consistency snapshot is created for a
virtual machine of a production site at a disaster
backup site. Specifically, a disaster tolerance management device determines a
virtual machine whose consistency snapshot needs to be provided according to user demand or
system configuration, determines an identifier of the
virtual machine, sends a consistency snapshot request to a
virtualization management device, the
virtualization management device forwards the consistency snapshot request to IOCFs in a host where the virtual
machine is, the IOCFs export IO data related with virtual
machine consistency, and perform snapshot identification on the IO data. Based on the abovementioned disaster tolerance process, when the IO data are transmitted to IOWFs of the host where a disaster
backup virtual
machine of a disaster
backup site is, and in the process of writing the IO data by the IOWFs, the snapshot identifier of the IO data is identified, and a disc snapshot is created at a finish point of the consistency snapshot corresponding to the snapshot identifier, thereby establishing consistency snapshots of all discs of the virtual machine at the disaster
backup site.