A technique for adaptive batching for asynchronous data redundancy. A
sequence of write transactions are adaptively arranged into a sequence of
send batches at the first storage facility. The transactions are received
at a second storage facility and applied to a redundant data copy at the
second storage facility. The second storage facility may arrange the
write transactions according to a sequence of receive batches. The batch
sizes may be adaptively adjusted or completed. The batch sizes or
adaptive completion of the batches may be based on, for example,
availability of a communication medium between the first storage facility
and the second storage facility. Each send batch may be forwarded to the
second storage facility upon completion.