A method, apparatus and program storage device for maintaining data
consistency and cache coherency during communications failures between
nodes in a remote mirror pair. A link between a mirror pair of storage
systems is monitored. During a link failure between a first storage
system and a second storage systems, reads and writes on the first and
second storage systems are independently performed and write data and
associated timestamps are maintained for the write data for each write in
a queue on the first and second storage system. After link
reestablishment, volume sets on the first and second storage systems are
resynchronized using write data and associated timestamps.