Concurrently replicating a plurality of storage devices includes disabling
writes to all of the storage devices, setting a pending state change
indicator for all of the storage devices after disabling writes without
altering a replication state of any of the storage devices, and enabling
writes to the storage devices after setting the pending state change
indicator. An I/O operation to a particular one of the storage devices
having a set pending state change indicator may cause the replication
state of the particular one of the storage devices to change to provide
for replication. Concurrently replicating a plurality of storage devices
may include, following changing the replication state of the particular
one of the storage devices, clearing the pending state change indicator.