A method is provided, comprising: receiving, from a host device, a request to create a token that represents one or more data items that are stored in a first volume, the first volume being stored in a source system; estimating an I/O latency limit for the first volume; estimating a token creation time for the token; comparing the token creation time to the I/O latency limit; when the token creation time matches the I/O latency limit: creating the token, creating a snapshot pair, mapping the token to the snapshot pair, and returning the token to the host device; when the token creation time does not match the I/O latency limit: creating the token, creating a first snapshot of the first volume at the source system, mapping the first snapshot to the token, and returning the token to the host device.