1. A computer-implemented system for backing up a plurality of virtual machines, the system comprising at least one processor and operatively associated memory, wherein the at least one processor is programmed to: receive data describing an input/output load for each of the plurality of virtual machines; initiate creation of a snapshot for each of the plurality of virtual machines at a snapshot time; select a first virtual machine from the plurality of virtual machines based on the data describing the input/output load for each of the plurality of virtual machines; generate a backup archive of the first virtual machine based on the snapshot for the first virtual machine; after beginning to generate the backup archive of the first virtual machine, select a second virtual machine from the plurality of virtual machines based on the data describing the input/output load for each of the plurality of virtual machines; and generate a backup archive of the second virtual machine based on the snapshot for the second virtual machine.